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1. Messages by category t type number previous difference convention 7 7 t refactor 0 0 warning 1 1 error 0 0 Messages message id occurrences invalid name 5 no space before operator 1 missing docstring 1 deprecated modul 1 Global evaluation Your code has been rated at 5 79 10 Wow That s a lot of stuff The first part is the messages section while the second part is the report section There are two points I want to tackle here First point is that all the tables of statistics i e the report are a bit overwhelming so I want to silence them To do 38 Chapter 11 A Beginner s Guide to Code Standards in Python Pylint Tutorial Pylint Documentation Release 1 5 0 that I will use the reports n option Tip Many of Pylint s commonly used command line options have shortcuts for example abbreviated to rn Pylint s man page lists all these shortcuts reports n can be Second previous experience taught me that the default output for the messages needed a bit more info We can see the first line is Cr 1 Missing docstring missing docstring This basically means that line 1 violates a convention C It s telling me I really should have a docstring I agree but what if I didn t fully unders
2. Julien Cristau Emile Anclin Logilab python 3 support Sandro Tosi Debian packaging Mads Kiilerich Boris Feld Bill Wendling Sebastian Ulrich various patches Brian van den Broek windows installation documentation Amaury Forgeot d Arc check names imported from a module exists in the module Benjamin Niemann allow block level enabling disabling of messages Nathaniel Manista suspicious lambda checking David Shea invalid sequence and slice index Carl Crowder don t evaluate the value of arguments for dangerous default value Michal Nowikowski wrong spelling in comment wrong spelling in docstring parallel execution on multiple CPUs and other patches David Lindquist logging format interpolation warning Brett Cannon Port source code to be Python 2 3 compatible Python 3 checker Vlad Temian redundant unittest assert and the JSON reporter Cosmin Poiean unichr builtin and improvements to bad open mode Viorel tirbu intern builtin warning Dan Goldsmith support for msg template in HTML reporter Chris Rebert unidiomatic typecheck Steven Myint duplicate except Radu Ciorba not context manager and confusing with statement warnings Bruno Daniel check docs extension James Morgensen ignored modules option applies to import errors Wolfgang Grafen Axel Muller Fabio Zadrozny Pierre Rouleau Maarten ter Huurne Mirko Friedenhagen and all the Logilab s team among others bug reports feedback feature r
3. new refile option to specify the configuration file without the PYLINTRC environment variable added an example module for a custom pylint checker see the example directory some fixes to handle fixes in common 0 9 1 should however still working with common 0 9 0 even if upgrade is recommended 2005 01 20 0 6 0 refix pylint emacs mode no more traceback when just typing pylint fix a bug which may cause crashes on resolving parent classes fix problems with the format checker don t chock on files containing multiple CR avoid C0322 C0323 C0324 false positives with triple quoted string with quote inside correctly detect access to member defined latter in init method now depends on common 0 8 1 to fix problem with interface resolution close 8606 new list msgs option describing available checkers and their messages added windows specific documentation to the README file contributed by Brian van den Broek updated doc features txt actually this file is now generated using the list msgs option more entries into the FAQ 74 Chapter 15 Changes amp Contributors Pylint Documentation Release 1 5 0 improved tests coverage 2004 10 19 0 5 0 avoid to import analyzed modules new Refactor and Convention message categories Some Warnings have been remaped into those new categories added similar a tool to find copied and pasted lines of code both using a specific command lin
4. Consider the following simplified example pylint function rgx P lt snake gt a z_ P lt camel gt _ A Z sample py The regular expression defines two naming styles snake for snake case names and came 1 for camel case names In sample py the function name on line 1 and 7 will mark the module and enforce the match of named group snake for the remaining names in the module def valid snake case arg def InvalidCamelCase arg def more valid snake case arg Because of this the name on line 4 will trigger an invalid name warning even though the name matches the given regex Matches named exempt or ignore can be used for non tainting names to prevent built in or interface dictated names to trigger certain naming styles name group namel name2 Default value empty Format comma separated groups of colon separated names This option can be used to combine name styles For example function method enforces that functions and methods use the same style and a style triggered by either name type carries over to the other This requires that the regular expression for the combined name types use the same group names 20 Chapter 6 Configuration Pylint Documentation Release 1 5 0 6 1 2 Name Hints include naming hint y n Default off Include a hint for the correct name format with every invalid name warning Name hints default to the regular expression b
5. Python 3 related fixes 110213 fix import of checkers broken with python 3 3 causing No such message id VV07047 breakage 120635 redefine cmp function used in pylint reporters Include full warning id for 10020 and 10021 and make sure to flush warnings after each module not at the end of the pylint run patch by Torsten Marek Changed the regular expression for inline options so that it must be preceeded by a patch by Torsten Marek 64 Chapter 15 Changes amp Contributors Pylint Documentation Release 1 5 0 Make dot output for import graph predictable and not depend on ordering of strings in hashes patch by Torsten Marek Add hooks for import path setup and move pylint s sys path modifications into them patch by Torsten Marek 2012 10 05 0 26 0 106534 add ignore imports option to code similarity checking and symilar command line tool patch by Ry4an Brase 104571 check for anomalous backslash escape introducing new VV 1401 and VV 1402 messages patch by Martin Pool 100707 check for boolop being used as exception class introducing new W0711 message patch by Tim Hatch 4014 improve checking of metaclass methods first args introducing new C0204 message patch by lothiraldan gmail com finalized by sthenault 4685 check for consistency of a module s all variable introducing new E0603 message 105337 allow custom reporter in output format patch by Kevin Jing Qiu
6. With Pylint lt 0 25 add pylint disable all at the beginning of the module Pylint 0 26 1 and up have renamed that directive to pylint skip file but the first version will be kept for backward compatibility In order to ease finding which modules are ignored a Information level message file ignored is emited With recent versions of Pylint if you use the old syntax an additional deprecated disable all message is emited 12 4 4 4 4 Do I have to remember all these numbers No starting from 0 25 3 you can use symbolic names for messages pylint disable fixme line too long 12 4 4 Message Control 43 Pylint Documentation Release 1 5 0 12 4 5 4 5 I have a callback function where have no control over received argu ments How do avoid getting unused argument warnings Prefix ui the callback s name by cb as in cb onclick By doing so arguments usage won t be checked Another solution is to use one of the names defined in the dummy variables configuration variable for unused argument _ and dummy by default 12 4 6 4 6 What is the format of the configuration file Pylint uses ConfigParser from the standard library to parse the configuration file It means that if you need to disable a lot of messages you can use tricks like disable wildcard import method hidden and too many lines because I do not want it disable wildcard import method hi
7. fixed some R0201 method could be a function false positive 2006 01 10 0 9 0 a lot of updates to follow astng 0 14 API changes so install logilab astng 0 14 or greater before using this version of pylint checker number 10 newstyle will search for problems regarding old style new style classes usage problems rely on astng 0 14 new style detection feature new load plugins options to load additional pylint plugins usable from the command line or from a configuration file implements 10031 check if a pylintrc file exists in the current working directory before using the one specified in the PYLINTRC environment variable or the default pylintre or etc pylintrc fixed W0706 Identifier used to raise an exception is assigned false positive and reraising a catched exception instance fixed E0611 No name get in module blabla false positive when accessing to a class dict fixed some E0203 access to member before its definition false positive fixed E0214 metaclass method first argument should be mcs false positive with staticmethod used on a metaclass fixed packaging which was missing the test regrtest data directory W0212 method could be a function has been reclassified in the REFACTOR category as R0201 and is no more considerer when a method overrides an abstract method from an ancestor class include module name in W0401 wildcard import as suggested by Amaury when using the
8. pylint enable no member error print self blip meth5 self test IF sub block re enabling pylint disable no member no error 13 Pylint Documentation Release 1 5 0 def def def print self bla if self blop pylint enable no member error print self blip else no error print self blip no error print self blip meth6 self test TRY EXCEPT sub block re enabling pylint disable no member no error print self bla try pylint enable no member error print self blip except UndefinedName pylint disable undefined variable no error print self blip no error print self blip meth7 self test one line block opening disabling if self blop pylint disable no member error print self blip else error print self blip error print self blip meth8 self test late disabling error print self blip pylint disable no member no error print self bla print self blop 14 Chapter 4 Messages control CHAPTER 5 Optional Pylint checkers in the extensions module 5 1 Parameter documentation checker If you document the parameters of your functions methods and constructors and their types systematically in your code this optional component might be useful for you Sphinx style Google style and Numpy style are supported For some examples see https pypi python org pypi sphinxcontrib napo
9. It is also possible to analyze python files with a few restrictions The thing to keep in mind is that Pylint will try to convert the file name to a module name and only be able to process the file if it succeeds pylint mymodule py should always work since the current working directory is automatically added on top of the python path pylint directory mymodule py will work if directory is a python package i e has an init py file or if directory is in the python path For more details on this see the Frequently Asked Questions You can also start a thin gui around Pylint require tkinter by typing pylint gui This should open a window where you can enter the name of the package or module to check at Pylint messages will be displayed in the user interface It is also possible to call Pylint from an other python program thanks to py run function in epylint module assuming Pylint options are stored in pylint options string as from pylint import epylint as lint lint py run pylint options To silently run Pylint on a module name py module and get its standard output and error from pylint import epylint as lint pylint stdout pylint stderr lint py run module name py return std True Pylint Documentation Release 1 5 0 2 2 Command line options First of all we have two basic but useful options version show program s version number
10. Remove interface not implemented warning Closes issue 5372 Remove the rest of interface checks interface is not class missing interface method unresolved interface The reason is that its better to start recommending ABCs instead of the old Zope era of interfaces One side effect of this change is that ignore iface methods becomes a noop it s deprecated and it will be removed at some time Emit a proper deprecation warning for reporters BaseReporter add message The alternative way is to use handle_message add_message will be removed in Pylint 1 6 Added new module extensions for optional checkers with the test directory test extensions and documenta tion file doc extensions rst 52 Chapter 15 Changes amp Contributors Pylint Documentation Release 1 5 0 Added new checker extensions check docs that verifies parameter documention in Sphinx Google and Numpy style Detect undefined variable cases where the definition of an undefined variable was in del statement Instead of emitting used before assignment which is totally misleading it now emits undefined variable Closes issue 528 Don t emit attribute defined outside init and access member before definition for mixin classes Actual errors can occur in mixin classes but this is controlled by the ignore mixin members option Closes issue 412 Improve the detection of undefined variables and variables used before assignment for va
11. 257 Don t emit unused variable when assigning to a nonlocal Closes issue 275 Do not let ImportError propagate from the import checker leading to crash in some namespace package related cases Closes issue 203 Don t emit pointless string statement for attribute docstrings Closes issue 193 Use the proper mode for pickle when opening and writing the stats file Closes issue 148 Don t emit hidden method message when the attribute has been monkey patched you re on your own when you do that Only emit attribute defined outside init for definition within the same module as the offended class avoiding to mangle the output in some cases Don t emit unnecessary lambda if the body of the lambda call contains call chaining Closes issue 243 Don t emit missing docstring when the actual docstring uses format Closes issue 281 2014 04 30 1 2 1 Restore the ability to specify the init hook option via the configuration file which was accidentally broken in 1 2 0 Add a new warning bad continuation for badly indentend continued lines Emit assignment from none when the function contains bare returns Fixes BitBucket issue 191 Added a new warning for closing over variables that are defined in loops Fixes Bitbucket issue 176 Do not warn about u escapes in string literals when Unicode literals are used for Python 2 Fixes Bit Bucket issue 151 Extend the checking for unbalanced tuple unpacking and
12. Release 1 5 0 Got a change for Pylint Below are a few steps you should take to make sure your patch gets accepted Test your code Pylint keeps a set of unit tests in the test directory The fest func py module uses external files to have some kind of easy functional testing To get your patch accepted you must write or change a test input file in the test input directory and message file in the test messages directory Then run python test func py to ensure that your test is green You should also run all the tests to ensure that your change isn t breaking one Add a short entry to the ChangeLog describing the change except for internal implementation only changes Write a comprehensive commit message Relate your change to an issue in the tracker if such an issue exists see this page of Bitbucket documentation for more information on this Send a pull request from Bitbucket more on this here 10 4 Unit test setup To run the pylint unit tests within your checkout without having to install anything you need to set PYTHONPATH so that pylint astroid and the logilab common are available Assume you have those packages in src If you have a normal clone of logilab common it will not be properly structured to allow import of logilab common To remedy this create the necessary structure cd src mkdir logilab mv logilab common logilab common touch logilab init p Now set PYTHONPATH to your src d
13. change enldis able msg cat options only accept message categories identified by their first letter eg IRCWEF without the need for comma as separator add epylint bat script to fix Windows installation setuptools easy install support 68 Chapter 15 Changes amp Contributors Pylint Documentation Release 1 5 0 include a modified version of Maarten ter Huurne patch to avoid W0613 warning on arguments from overridden method implement 5575 drop dumb W0704 message by adding W0704 to ignored messages by default new WO108 message checking for suspicious lambda provided by Nathaniel Manista fix W0631 false positive reported by Paul Hachmann fix 6951 false positive with W0104 fix 6949 patches by Mads Kiilerich implement 4691 make pylint exits with a non zero return status if any messages other then Information are issued fix 3711 5626 name resolution bug w decorator and class members fix 6954 2008 10 13 0 15 2 fix 5672 W0706 weirdness W0706 removed fix 5998 documentation points to wrong url for mailing list fix 6022 no error message on wrong module names fix 6040 pytest doesn t run test func test py 2008 09 15 0 15 1 fix 4910 default values are missing in manpage fix 5991 missing files in 0 15 0 tarball fix 5993 epylint should work with python 2 3 2008 09 10 0 15 0 include pyreverse package and class diagram generation included Stefan Rank s patch to deal wit
14. lt x y Similarly you may provide different message files for a single input message file whose name ends with py xy txt will be used for Python gt x y using the nearest version possible class article 10 5 Adding new functional tests 33 Pylint Documentation Release 1 5 0 34 Chapter 10 Contribute CHAPTER 11 A Beginner s Guide to Code Standards in Python Pylint Tutorial Author Robert Kirkpatrick For a detailed description of Pylint see http www pylint org 11 1 Intro Beginner to coding standards Pylint can be your guide to reveal what s really going on behind the scenes and help you to become a more aware programmer Sharing code is a rewarding endeavor Putting your code out there can be either an act of philanthropy coming of age or a basic extension of belief in open source Whatever the motivation your good intentions may not have the desired outcome if people find your code hard to use or understand The Python community has formalized some recommended programming styles to help everyone write code in a common agreed upon style that makes the most sense for shared code This style is captured in PEP 8 Pylint can be a quick and easy way of seeing if your code has captured the essence of PEP 8 and is therefore friendly to other potential users Perhaps you re not ready to share your code but you d like to learn a bit more about writing better code and don t know where
15. py3k when the appropriate built in is not used in an iterating context semantics taken from 2to3 e Add a new warning unidiomatic typecheck emitted when an explicit typecheck uses type instead of isin stance For example type x Y instead of isinstance x Y Patch by Chris Rebert Closes issue 299 e Add support for combining the Python 3 checker mode with the jobs flag py3k and jobs Closes issue 467 Add a new warning for the Python 3 porting checker using cmp argument emitted when the cmp argument for the list sort or sorted builtin is encountered e Make the py3R flag commutative with the E flag Also this patch fixes the leaks of error messages from the Python 3 checker when the errors mode was activated Closes issue 437 2015 01 16 1 4 1 Look only in the current function s scope for bad super call Closes issue 403 Check the return of properties when checking for not callable Closes issue 406 Warn about using the input or round built ins for Python 3 Closes issue 411 Proper abstract method lookup while checking for abstract class instantiated Closes issue 401 Use a mro traversal for finding abstract methods Closes issue 415 Fix a false positive with catching non exception and tuples of exceptions Fix a false negative with raising non exception when the raise used an uninferrable exception context 56 Chapter 15 Changes amp Contributors
16. 104420 check for protocol completness and avoid false R0903 patch by Peter Hammond 100654 fix grammatical error for W0332 message using I as long int identifier 103656 fix W0231 false positive for missing call to object init patch by lothiraldan gmail com 03424 fix similarity report disabling by properly renaming it to RP0801 103949 create a console scripts entry point to be used by easy install buildout and pip fix cross interpreter issue non compatible access to __builtins__ stop including tests files in distribution they causes crash when installed with python3 72022 82417 76910 2012 07 17 0 25 2 93591 Correctly emit warnings about clobbered variable names when an except handler contains a tuple of names instead of a single name patch by tmarek google com 7394 W0212 access to protected member not emited on assigments patch by lothiraldan O gmail com 18772 no prototype consistency check for mangled methods patch by lothiraldan O gmail com 92911 emit WO102 when sets are used as default arguments in functions patch by tmarek O google com 77982 do not emit E0602 for loop variables of comprehensions used as argument values inside a deco rator patch by tmarek google com 89092 don t emit E0202 attribute hiding a method on property methods 92584 fix pylint gui crash due to internal API change 87192 fix crash when decorators are accessed through more than one dot f
17. a pylintrc configuration file in the current folder if pylintrc is not found Dotted pylintrc files will not be searched in the parents of the current folder as it is done for pylintrc Add a new error invalid unary type operand emitted when an unary operand is used on something which doesn t support that operation for instance using the unary bitwise inversion operator on an instance which doesn t implement __invert__ Take in consideration differences between arguments of various type of functions classmethods staticmethods properties when checking for arguments differ Closes issue 548 astroid inspector was moved to pylint pyreverse since it belongs there and it doesn t need to be in astroid astroid utils LocalsVisitor was moved to pylint pyreverse Locals Visitor pylint checkers utils excepts import error was removed Use pylint chekcers utils error of type instead Don t emit undefined all variables for nodes which can t be inferred YES nodes yield outside func is also emitted for yield from Add a new error too many star expressions emitted when there are more than one starred expression x in an assignment The warning is emitted only on Python 3 Add a new error invalid star assignment target emitted when a starred expression x is used as the Ihs side of an assignment as in x 1 2 This is not a SyntaxError on Python 3 though Detect a couple of objects which can
18. documentation it should be clear and well documented Don t hesitate to ask for any information on the code quality mailing list 23 Pylint Documentation Release 1 5 0 24 Chapter 7 Extending Pylint CHAPTER 8 Editor and IDE integration To use Pylint with Emacs see http www emacswiki org emacs PythonProgrammingInEmacs toc8 Vim see http www vim org scripts script php script_id 891 Eclipse and PyDev see http pydev org manual adv pylint html e Komodo see http mateusz loskot net posts 2006 01 15 running pylint from komodo e gedit see https launchpad net gedit pylint 2 or https wiki gnome org Apps Gedit PylintPlugin WingIDE see http www wingware com doc edit pylint e PyCharm see http blog saturnlaboratories co za archive 2012 09 10 running pylint pycharm TextMate Pylint is integrated in Eric IDE see the Project Check menu Spyder see http packages python org spyder pylint html pyscripter see the Tool gt Tools menu 8 1 Using Pylint thru flymake in Emacs To enable flymake for Python insert the following into your emacs Configure flymake for Python when load flymake t defun flymake pylint init Letx temp file flymake init create temp buffer copy flymake create temp inplace local file file relative name temp file file name directory buffer file name list epylint list local file add to list flymake allowed fil
19. for all the builtins and not as a special case for the reversed builtin This will happen shortly in the future comment flag is obsolete and it will be removed in Pylint 1 6 profile flag is obsolete and it will be removed in Pylint 1 6 Add a new error misplaced bare raise The error is used when a bare raise is not used inside an except clause This can generate a RuntimeError in Python if there are no active exceptions to be reraised While it works in Python 2 due to the fact that the exception leaks outside of the except block it s nevertheless a behaviour that an user shouldn t depend upon 54 Chapter 15 Changes amp Contributors Pylint Documentation Release 1 5 0 since it s not obvious to the reader of the code what exception will be raised and it will not be compatible with Python 3 anyhow Closes issue 633 Bring logilab common s ureports into pylint reporters With this change we moved away from depending on logilab common having in Pylint all the components that were used from logilab common The API should be considered an implementation detail and can change at some point in the future Closes issue 621 reimported is emitted for reimported objects on the same line Closes issue 639 Abbreviations of command line options are not supported anymore Using abbreviations for CLI options was never considered to be a feature of pylint this fact being only a side effect of using optparse As this
20. locals for attr in self WARNING DETAILS setattr self attr local values attr self category name category name if category else None def str self Ah the fields message category etc are not defined statically on the class Instead they are added using setattr Pylint would have a tough time figuring this out 29 Pylint Documentation Release 1 5 0 9 3 Enter Plugin We can write a plugin to tell Pylint about how to analyze this properly A plugin is a module which should have a function register and takes the lint module as input So a basic hello world plugin can be implemented as Inside hello plugin py def register linter print Hello world We can run this plugin by placing this module in the PYTHONPATH and invoking as amitdevS pylint E load plugins hello plugin foo py Hello world Back to our example one way to fix that would be to transform the WarningMessage class and set the attributes using a plugin so that Pylint can see them This can be done by registering a transform function We can transform any node in the parsed AST like Module Class Function etc In our case we need to transform a class It can be done SO from astroid import MANAGER from astroid import scoped nodes def register linter pass def transform cls if cls name WarningMessage import warnings for f in warnings WarningMessage WARNING DETAILS cls locals f
21. of lt gt and 1 as long int marker major internal API changes use the rewrite of astng based on compiler ast added unique id for messages as suggested by Wolfgang Grafen added unique id for reports can take multiple modules or files as argument new options command line options disable msg enable msg help msg include ids reports disable report cache size version shows the version of the python interpreter removed some options which are now replaced by enldis able msg or disable report read disable msg and enable msg options in source files should be in comments on the top of the file in the form pylint disable msg W0402 new message for modules importing themselves instead of the cyclic import message fix bug with relative and cyclic imports fix bug in imports checker cycle was not always detected still fixes in format checker don t check comment and docstring check first line after an indent black and white list now apply to all identifiers not only variables so changed the configuration option from goodlbad variable names to goodibad names 76 Chapter 15 Changes amp Contributors Pylint Documentation Release 1 5 0 added string rexec and Bastion to the default list of deprecated modules do not print redefinition warning for function class method defined in mutually exclusive branches 2003 10 10 0 2 1 added some documentation fix
22. of their python program using the translator of the PyPy project For more information about PyPy or RPython visit http codespeak net pypy new E0104 and E0105 messages introduced to respectively warn about return and yield outside func tion or method new E0106 message when yield and return something are mixed in a function or method new WO107 message for unnecessary pass statement new W0614 message to differentiate between unused import X and unused from X import 3209 patch submitted by Daniel Drake included Daniel Drake s patch to have a different message E1003 instead of E1001 when a missing member is found but an inference failure has been detected msvs reporter for Visual Studio line number reporting 3285 allow disable all option inline 3218 patch submitted by Daniel Drake init hook option to call arbitrary code necessary to set environment eg sys path 3156 One more Daniel s patch fixing a command line option parsing problem this ll definitely be the DDrake release fix 3184 crashes on return outside function fix 3205 W0704 false positive fix 3123 W0212 false positive on static method fix 2485 W0222 false positive fix 3259 when a message is explicitly enabled check the checker emitting it is enabled 2006 11 23 0 12 2 fix 3143 W0233 bug w YES objects fix 3119 Off by one error counting lines in a file fix 3117 ease sys stdout overriding for reporters fix
23. parseable path are written relative to the current working directory if in a sub directory of it 9789 pylint version shows logilab astng and logilab common versions 72 Chapter 15 Changes amp Contributors Pylint Documentation Release 1 5 0 fixed pylint el to handle space in file names misc lint style fixes 2005 11 07 0 8 1 fix deprecated module false positive when the code imports a module whose name starts with a depre cated module s name close 10061 fix module has no name __dict__ false positive close 10039 fix access to undefined variable __path__ false positive close 10065 fix explicit return in __init__ false positive when return is actually in an inner function close 10075 2005 10 21 0 8 0 check names imported from a module exists in the module E0611 patch contributed by Amaury Forgeot d Arc print a warning W0212 for methods that could be a function implements 9100 new defining attr methods option on classes checker new acquired members option on the classes checker used when zope yes to avoid false positive on acquired attributes listed using this new option close 8616 generate one E0602 for each use of an undefined variable previously only one for the first use but not for the following implements 1000 make profile option saveable fix Windows bat file patch contributed by Amaury Forgeot d Arc fix one more false
24. positive for E0601 access before definition with for loop such as for i in range 10 print i test func noerror defined and used on same line fix false positive for E0201 undefined member when accessing to name ona class object fix astng checkers traversal order fix bug in format checker when parsing a file from a platform using different new line characters close 9239 fix encoding detection regexp fix refile handling support for refile file close 9590 2005 05 27 0 7 0 WARNING pylint is no longer a logilab subpackage Users may have to manually remove the old logi lab pylint directory introduce a new additional builtins option to handle user defined builtins reports option has now r as short alias and i for include ids fix a bug in the variables checker which may causing some false positives when variables are defined and used within the same statement test func noerror defined and used on same line this time real fix of the disable msg in the config file problem test added to unittest lint fix bug with list messages and python OO fix possible false positive for W0201 2005 04 14 0 6 4 allow to parse files without extension when a path is given on the command line test noext 15 1 ChangeLog for Pylint 73 Pylint Documentation Release 1 5 0 don t fail if we are unable to read an inline option e g inside a module just produce an information message
25. scoped nodes Class f None MANAGER register transform scoped nodes Class transform Lets go through the plugin First we need to register a class transform which is done via the register transform function in MANAGER It takes the node type and function as parameters We need to change a class so we use scoped nodes Class We also pass a transform function which does the actual transformation transform function is simple as well If the class is WarningMessage then we add the attributes to its locals we are not bothered about type of attributes so setting them as class will do But we could set them to any type we want That s it Note We don t need to do anything in the register function of the plugin since we are not modifying anything in the linter itself Lets run Pylint with this plugin and see amitdev pylint E load plugins warning plugin Lib warnings py amitdevS All the false positives associated with WarningMessage are now gone This is just an example any code transfor mation can be done by plugins See nodes and scoped nodes for details about all node types that can be transformed 30 Chapter 9 Plugins CHAPTER 10 Contribute 10 1 Bug reports feedback You think you have found a bug in Pylint Well this may be the case since Pylint is under development Please take the time to check if it is already in the issue tracker at https bitbucket org logilab p
26. t be base classes bool slice range and memoryview which weren t detected until now 15 1 ChangeLog for Pylint 53 Pylint Documentation Release 1 5 0 Add a new error for the Python 3 porting checker import star module level which is used when a star import is detected in another scope than the module level which is an error on Python 3 Using this will emit a SyntaxWarning on Python 2 Add a new error star needs assignment target emitted on Python 3 when a Starred expression x is not used in an assignment target This is not caught when parsing the AST on Python 3 so it needs to be a separate check Add a new error unsupported binary operation emitted when two a binary arithmetic operation is executed between two objects which don t support it a number plus a string for instance This is currently disabled since the it exhibits way too many false positives but it will be reenabled as soon as possible New imported features from astroid into pyreverse pyreverse inspector Project pyre verse inspector project from files and pyreverse inspector interfaces These were moved since they didn t belong in astroid Enable misplaced future for Python 3 Closes issue 580 Add a new error nonlocal and global which is emitted when a name is found to be both nonlocal and global in the same scope Closes issue 581 ignored classes option can work with qualified names ignored classes optparse Values C
27. to make some modifications in our code to please Pylint stick to more naming conventions unused variables ending in underscores mix in class names ending in Mixin making all abstract methods explicit rather than just not defining them in the superclass Pylint Documentation Release 1 5 0 e add pylint disable X0123 comments for messages which are useful in general but not in a specific case for Pylint bugs for Pylint limitations for instance Twisted s modules create a lot of definitions dynamically so Pylint does not know about them The effort is worth it since Pylint helps us a lot in keeping the code clean and finding errors early Although most errors found by Pylint would also be found by the regression tests by fixing them before committing we save time And our regression tests do not cover all code either just the most complex parts 4 Chapter 1 Introduction CHAPTER 2 Running Pylint 2 1 Invoking Pylint Pylint is meant to be called from the command line The usage is pylint options module or package You should give Pylint the name of a python package or module Pylint will not import this package or module though uses Python internals to locate them and as such is subject to the same rules and configuration You should pay attention to your PYTHONPATH since it is a common error to analyze an installed version of a module instead of the development version
28. transforms such calls if it can into the final resulting string and this exhibit a problem because the visit binop method stops being called in the optimized AST it will be a Const node 2015 03 11 1 4 2 Don t require a docstring for empty modules Closes issue 261 Fix a false positive with too few format args string warning emitted when the string format contained a normal positional argument 0 mixed with a positional argument which did an attribute access 0 __class__ Closes issue 463 Take in account all the methods from the ancestors when checking for too few public methods Closes issue 471 e Catch enchant errors and emit invalid characters in docstring when checking for spelling errors Closes issue 469 e Use all the inferred statements for the super init not called check Closes issue 389 e Add a new warning unichr builtin emitted by the Python 3 porting checker when the unichr builtin is found Closes issue 472 e Add a new warning intern builtin emitted by the Python 3 porting checker when the intern builtin is found Closes issue 473 Add support for editable installations The HTML output accepts the msg template option Patch by Dan Goldsmith e Add map builtin not iterating replacing implicit map evaluation zip builtin not iterating range builtin not iterating and filter builtin not iterating which are emitted by
29. was the case using load plugin or other abbreviation for load plugins never actually worked while it also didn t raise an error Closes issue 424 Add a new error nonlocal without binding The error is emitted on Python 3 when a nonlocal name is not bound to any variable in the parents scopes Closes issue 582 deprecated module can be shown for modules which aren t available Closes issue 362 Don t consider a class abstract if its members can t be properly inferred This fixes a false positive related to abstract class instantiated Closes issue 648 Add a new checker for the async features added by PEP 492 Add a new error yield inside async function emitted on Python 3 5 and upwards when the yield statement is found inside a new coroutine function PEP 492 Add a new error not async context manager emitted when an async context manager block is used with an object which doesn t support this protocol PEP 492 Add a new convention warning singleton comparison emitted when comparison to True False or None is found Don t emit assigning non slot for descriptors Closes issue 652 Add a new error repeated keyword when a keyword argument is passed multiple times into a function call This is similar with redundant keyword arg but it s mildly different that it needs to be a separate error enable all can now be used Closes issue 142 Add a new convention message mispla
30. 2508 E0601 false positive with lambda fix 3125 E1101 false positive and a message duplication Only the last part is actually fixed since the initial false positive is due to dynamic setting of attributes on the decimal Context class fix 3149 E0101 false positives and introduced E0100 for generator init X methods fixed some format checker false positives 70 Chapter 15 Changes amp Contributors Pylint Documentation Release 1 5 0 2006 09 25 0 12 1 fixed python gt 2 4 format false positive with multiple lines statement fixed some 2 5 issues fixed generator expression scope bug depends on astng 0 16 1 stop requiring revision 2006 08 10 0 12 0 usability changes parseable html and color options are now handled by a single output format option enable checkerid and disable all options are now handled by two exclusive enable checker and disable checker options taking a comma separated list of checker names as value renamed debug mode option to errors only started a reference user manual new W0212 message for access to protected member from client code close 14081 new W0105 and W0106 messages extracted from W0104 statement seems to have no effect respectively when the statement is actually string that s sometimes used instead of comments for documentation or an empty statement generated by a useless semicolon reclassified W0302 to C0302 fix so that global messages are not any
31. 4 Check that various built ins that do not exist in Python 3 are not used apply basestring buffer cmp coerce execfile file long raw input reduce StandardError unicode reload and xrange Warn for magic methods which are not used in any way in Python 3 coerce delslice getslice setslice__ __cmp__ oct nonzero and hex Don t emit assigning non slot when the assignment is for a property Closes issue 359 58 Chapter 15 Changes amp Contributors Pylint Documentation Release 1 5 0 Fix for regression path was no longer accepted in msg template Report the percentage of all messages not just for errors and warnings Closes issue 319 too many public methods is reported only for methods defined in a class not in its ancestors Closes issue 248 too many lines disable pragma can be located on any line not only the first Closes issue 321 Warn in Python 2 when an import statement is found without a corresponding from __future__ import abso lute_import Warn in Python 2 when a non floor division operation is found without a corresponding from __future__ import division Add a new option exclude protected for excluding members from the protected access warning Closes issue 848 Warn in Python 2 when using dict iter dict view none of these methods are available in Python 3 Warn in Python 2 when calling an object s next method Python 3 uses next i
32. Pylint Documentation Release 1 5 0 Fix a false positive on Python 2 for raising bad type when raising tuples in the form raise ZeroDivisionError None Fix a false positive with invalid slots objects where the slot entry was an unicode string on Python 2 Closes issue 421 Add a new warning redundant unittest assert emitted when using unittest s methods assertTrue and assert False with constant value as argument Patch by Vlad Temian Add a new JSON reporter usable through f flag e Add the method names for the signature differs and argument differs warnings Closes issue 433 Don t compile test files when installing Fix acrash which occurred when using multiple jobs and the files given as argument didn t exist at all 2014 11 23 1 4 0 Added new options for controlling the loading of C extensions By default only C extensions from the stdlib will be loaded into the active Python interpreter for inspection because they can run arbitrary code on import The option extension pkg whitelist can be used to specify modules or packages that are safe to load Change default max line length to 100 rather than 80 Drop BaseRawChecker class which were only there for backward compat for a while now Don t try to analyze string formatting with objects coming from function arguments Closes issue 373 Port source code to be Python 2 3 compatible This drops the need for 2to3 but does drop s
33. Pylint Documentation Release 1 5 0 Logilab and contributors November 19 2015 Contents 10 Introduction Val Whatas PYNE a tet rada r 64d bee de eS 1 2 What Pylintis mot es se kee a EAS OR Running Pylint 2 1 Invoking Pylint e e an eee ae eee Oe hae PRA Rs 2 2 Command line options isos eee den en d 23 Parallel execution sn oo nee 42602235444 4044 SEN Pylint output 3 1 Seurcecodeanalysissecti n iii RY SG 6a oda 3 2 Reports Section s ea ve ee Ros Y Y RORIS Es GR SOS Messages control Optional Pylint checkers in the extensions module 5 1 Parameter documentation checker Configuration 6 Naming Styles oe re cec nis Rb ok v bee ee ea ee EE Extending Pylint T4 Wntngyourown checker 4 aa sa we zon ger e Editor and IDE integration 8 1 Using Pylint thru flymake in Emacs llle 8 2 Setup the MS Visual Studio NET 2003 editor to call Pylint 8 3 Integrate Pylint with TextMate o e o se co o o Re Plugins 9 Why wnte plugin sea anne we vat OS A ES YO Se R 9 2 Example e sos getoa E a Ree tae ean ees 9 39 Enter Plugin e so i dee Re ER dm BER ee sea Contribute 10 1 Bus reports feedback ooh e EROR REX RR 10 2 Mailing ds 4 2 deis a are ommo RR ERR e Go oe ER Do 10 3 o P ae ern a en do eo Be nn 10 4 Umttestsetup 2 52 oso ed ee bbe REUS Sak doses 13 15 Kos BE Re ge ed ge 15 19 Dr 19 23 IRL 23 25 bo
34. and exit h help show help about the command line options Pylint is architectured around several checkers By default all checkers are enabled You can disable a specific checker or some of its messages or messages categories by specifying disable id If you want to enable only some checkers or some message ids first use disable all then enable lt id gt with id being a comma separated list of checker names and message identifiers See the list of available features for a description of provided checkers with their functionalities The disable and enable options can be used with comma separated lists mixing checkers message ids and categories like d C W E0611 design It is possible to disable all messages with disable all This is useful to enable only a few checkers or a few messages by first disabling everything and then re enabling only what you need Each checker has some specific options which can take either a yes no value an integer a python regular expression or a comma separated list of values which are generally used to override a regular expression in special cases For a full list of options use help Specifying all the options suitable for your setup and coding standards can be tedious so it is possible to use a configuration file to specify the default values You can specify a configuration file on the command line using the rcfile option Otherwise Pylint searches for a configuration file
35. and line option 20 variable rgx lt regex gt command line option 20 A article built in class 33 C command line option argument rgx lt regex gt 20 attr rgx lt regex gt 19 class attribute rgx lt regex gt 20 class rgx lt regex gt 19 const rgx lt regex gt 19 function rgx lt regex gt 19 include naming hint yln 21 inlinevar rgx lt regex gt 20 method rgx lt regex gt 19 module rgx lt regex gt 19 name group lt namel name2 S 20 variable rgx lt regex gt 20 81
36. b e gn Bde Be bees 5 25 T I 27 de RA Sr Bodiam e BR SOR 27 11 12 13 14 15 16 10 5 Adding new tunctionaltestS uu nos RR Ey oko RR a Rh m Oe D RAE IR RR RR Rn A Beginner s Guide to Code Standards in Python Pylint Tutorial ILT IMO A ITI 11 2 GENESIS ouo qe oue Sade ee tite OP Due dures ogni oe de fe Ha delito qe Rie ee 11 3 Your First Pylintine lt ses pe on see ERG ur PE eR Pe dus E E 11 4 The Next Step i256 24524248 Rok Ro EE Rex uo Rode SUME qo EE Se o Frequently Asked Questions 12 d About Pylnt 223 a oh ak Bok we ae RR af Sok ck as eh e Ra de te ae EE aces d Ge 12 2 2 Installation opone tok RE Roh e Robo des Phe wee ee eed ee A 12 3 3s Runmns PVE tt edo eek en SSS NOR EES de CEDE SS 12 4 4 Message Control se recom st ER SE HA EAS RR Ee ae SUEDE AVE eus 12 5 Se Classes and Inheritance see trios WAS eae de we EP Oo en E SEES ES 12 67 16 Iroubleshooume p 5 pre rhetor ew Pc bete doe ur arena be del ge ede Some projects using Pylint Installation 14 1 Dependenties seep mom ro de ee eee See eee SRF GRON RO ROS E E RO nde ke KO GR pa 14 2 Distributions 1o Relo er 224 2 Seed bee Dee ha Boh n 3 Od 3 xA ROS oe od 14 3 Python packages 2x ma ee n RE ey Es OE HO EAS SER Eee X BD Rus 14 4 Source distribution installation lt a oe s sas sa sa RR IRA be ua p HRS 14 5 Note for Windows users oes pe dem ee Bae Sox A Robe ie bug x dom EE EUR RS Changes a
37. blah exit with status 2 66 Chapter 15 Changes amp Contributors Pylint Documentation Release 1 5 0 update documentation 2010 09 28 0 21 3 restored python 2 3 compatibility Along with logilab astng 0 21 3 and logilab common 0 52 this will much probably be the latest release supporting python 2 5 2010 08 26 0 21 2 fix 36193 import checker raise exception on cyclic import fix 28796 regression in generated members introduced pylint 0 20 some documentation cleanups 2010 06 04 0 21 1 fix 28962 pylint crash with new options due to missing stats data while writing the Statistics by types report updated man page to 0 21 or greater command line usage fix debian 582494 2010 05 11 0 21 0 command line updated closes 9774 9787 9992 22962 all enable disable options have been merged into enable disable BACKWARD INCOMPATIBLE CHANGE short name of errors only becomes E e being affected to enable pylint help output much simplified with long help available to get the complete one revisited gui thanks to students from Toronto university they are great contributors to this release fix 21591 html reporter produces no output if reports is set to no fix 4581 not Missing docstring CO111 warning if a method is overridden fix 4683 Non ASCII characters count double if utf8 encode fix 9018 when using defining attr method method ord
38. ced comparison constant emitted when a constant is placed in the left hand side of a comparison as in 5 func This is also called Yoda condition since the flow of code reminds of the Star Wars green character conditions usually encountered in languages with variabile assignments in conditional statements Add a new convention message consider using enumerate which is emitted when code that uses range and len for iterating is encountered Closes issue 684 Added two new refactoring messages no classmethod decorator and no staticmethod decorator which are emitted when a static method or a class method is declared without using decorators syntax Closes issue 675 2015 03 14 1 4 3 Remove three warnings star args abstract class little used abstract class not used These warnings don t add any real value and they don t imply errors or problems in the code 15 1 ChangeLog for Pylint 55 Pylint Documentation Release 1 5 0 e Added a new option for controlling the peephole optimizer in astroid The option optimize ast will control the peephole optimizer which is used to optimize a couple of AST subtrees The current problem solved by the peephole optimizer is when multiple joined strings with the addition operator are encountered If the numbers of such strings is high enough Pylint will then fail with a maximum recursion depth exceeded error due to its visitor architecture The peephole just
39. checks for style issues while Pychecker explicitly does not There are a few other differences such as the fact that Pylint does not import live modules while Pychecker does see 6 2 Why does Pychecker catch problems with imports that Pylint doesn t 12 1 3 1 3 Who wrote Pylint Pylint s main author and maintainer for the first ten years of its life has been Sylvain Th nault while he worked at Logilab where the project was born For a full list of contributors see the Contributors section of Pylint s README file 12 1 4 1 4 Who uses Pylint Everybody knows someone who uses Pylint 12 2 2 Installation 12 2 1 2 1 How do install Pylint Everything should be explained on http docs pylint org installation 41 Pylint Documentation Release 1 5 0 12 2 2 2 2 What kind of versioning system does Pylint use Pylint uses the Mercurial distributed version control system The URL of the repository is https bitbucket org logilab pylint To get the latest version of Pylint from the repository simply invoke hg clone https bitbucket org logilab pylint 12 2 3 2 3 What are Pylint s dependencies Pylint requires the latest astroid and logilab common packages It should be compatible with any Python version greater than 2 7 0 12 2 4 2 4 What versions of Python is Pylint supporting Since Pylint 1 4 we support only Python 2 7 and Python 3 3 Using this strategy really helps in maintaining a code base co
40. contain usr local bin An actual example in this case might be SPATH opt local bin usr local bin usr texbin which includes other paths and try running Pylint again 28 Chapter 8 Editor and IDE integration CHAPTER 9 Plugins 9 1 Why write a plugin Pylint is a static analysis tool and Python is a dynamically typed language So there will be cases where Pylint cannot analyze files properly this problem can happen in statically typed languages also if reflection or dynamic evaluation is used Plugin is a way to tell Pylint how to handle such cases since only the user would know what needs to be done 9 2 Example Let us run Pylint on a module from the Python source warnings py and see what happens amitdev pylint E Lib warnings py 297 36 Instance of WarningMessage has no message member no member 298 36 Instance of WarningMessage has no filename member no member 298 51 Instance of WarningMessage has no lineno member no member 298 64 Instance of WarningMessage has no line member no member E pd H d Did we catch a genuine error Let s open the code and look at WarningMessage class class WarningMessage object Holds the result of a single showwarning call WARNING DETAILS message category filename lineno file line def init self message category filename lineno file None line None local values
41. ct the Bundles tab 3 find and tick the Python bundle in the list You should now see it in Bundles gt Python In Preferences select the Variables tab If a TM PYCHECKER variable is not already listed add it with the value pylint The default keyboard shortcut to run the syntax checker is Control Shift V open a py file in Textmate and try it You should see the output in a new window PyCheckMate 1 2 Pylint 1 4 4 No config file found using default configuration 8 2 Setup the MS Visual Studio NET 2003 editor to call Pylint 27 Pylint Documentation Release 1 5 0 Then all is well and most likely Pylint will have expressed some opinions about your Python code or will exit with 0 if your code already conforms to its expectations If you receive a message Please install PyChecker PyFlakes Pylint PEP 8 or flake8 for more extensive code checking That means that Pylint wasn t found which is likely an issue with command paths TextMate needs be looking for Pylint on the right paths Check where Pylint has been installed using which which pylint usr local bin pylint The output will tell you where Pylint can be found in this case in usr 10cal bin 1 select TextMate gt Preferences 2 select the Variables tab 3 find and check that a PATH variable exists and that it contains the appropriate path if the path to Pylint were usr local bin pylint as above then the variable would need to
42. d context manager error checking that __exit__ arguments special method accepts the right number of Run pylint as a python module python m pylint anatoly techtonik Check for non exception classes inside an except clause epylint support options to give to pylint after the file to analyze and have basic input validation bitbucket 53 and 54 patches provided by felipeochoa and Brian Lane Added a new warning non iterator returned for non iterators returned by iter Add new checks for unpacking non sequences in assignments unpacking non sequence as well as unbal anced tuple unpacking unbalanced tuple unpacking useless else on loop not emited if there is a break in the else clause of inner loop 117 don t mark input as a bad function when using python3 110 badly implemented container caused several problems in its current implementation Deactivate it until we have something better See 112 for instance Use attribute regexp for properties in python3 as in python2 Create the PYLINTHOME directory when needed it might fail and lead to spurious warnings on import of pylint config Fix setup py so that pylint properly install on Windows when using python3 Various documentation fixes and enhancements Fix issue 55 false positive trailing whitespace on Windows 2013 08 06 1 0 0 Add check for the use of exec function New msg template option to control output deprecating ms
43. dden too many lines 12 5 5 Classes and Inheritance 12 5 1 5 1 When is Pylint considering a class as an abstract class A class is considered as an abstract class if at least one of its methods is doing nothing but raising NotImplemented Error 12 5 2 5 2 How do avoid access to undefined member messages in my mixin classes To do so you have to set the ignore mixin members option to yes this is the default value and to name your mixin class with a name which ends with mixin whatever case 12 6 6 Troubleshooting 12 6 1 6 1 Pylint gave my code a negative rating out of ten That can t be right Even though the final rating Pylint renders is nominally out of ten there s no lower bound on it By default the formula to calculate score is 10 0 float 5 x error warning refactor convention statement 2 10 However this option can be changed in the Pylint rc file If having negative values really bugs you you can set the formula to be the maximum of 0 and the above expression 12 6 2 6 2 Why does Pychecker catch problems with imports that Pylint doesn t Pychecker and Pylint use different approaches pychecker imports the modules and rummages around in the result hence it sees my mangled sys path Pylint doesn t import any of the candidate modules and thus doesn t include any of import s side effects good and bad It traverses an AST representation of the code 44 Chapter 12 Freq
44. e 303 Order of reporting is consistent Add a new warning boolean datetime emitted when an instance of datetime time is used in a boolean context Closes issue 239 Fix a crash which ocurred while checking for method hidden when the parent frame was something different than a function Generate html output for missing files Closes issue 320 Fix a false positive with too many format args when the format string contains mixed attribute access argu ments and manual fields Closes issue 322 Extend the cases where undefined variable and used before assignment can be detected Closes issue 291 Add support for customising callback identifiers by adding a new callbacks command line option Closes issue 326 Add a new warning logging format interpolation emitted when format string interpolation is used within logging function calls Don t emit unbalanced tuple unpacking when the rhs of the assignment is a variable length argument Closes issue 329 Add a new warning inherit non class emitted when a class inherits from something which is not a class Closes issue 331 Fix another false positives with undefined variable where the variable can be found as a class assignment and used in a function annotation Closes issue 342 Handle assignment of the string format method to a variable Closes issue 351 Support wheel packaging format for PyPi Closes issue 33
45. e name masks NN pyN V flymake pylint init Set as a minor mode for Python add hook python mode hook lambda flymake mode 25 Pylint Documentation Release 1 5 0 Above stuff is in pylint elisp pylint flymake el which should be automatically installed on Debian systems in which cases you don t have to put it in your emacs file Other things you may find useful to set Configure to wait a bit longer after edits before starting setq default flymake no changes timeout 3 Keymaps to navigate to the errors add hook python mode hook lambda define key python mode map XC cn flymake go add hook python mode hook lambda define key python mode map C cp flymake go Finally by default flymake only displays the extra information about the error when you hover the mouse over the highlighted line The following will use the minibuffer to display messages when you the cursor is on the line o next error O prev error To avoid having to mouse hover for the error message these functions make flymak appear in the minibuffer defun show fly err at point If the cursor is sitting on a flymake error display the message in the minibuffer require cl interactive let line no line number at pos dolist elem flymake err info if eq car elem line no let err car second elem message s flymake ler text err add hook p
46. e tool and integrated as a pylint s checker imports checker may report import dependencies as a dot graph new checker regrouping most Refactor detection with some new metrics more command line options storable in the configuration file fix bug with total undocumented number of methods 2004 07 08 0 4 2 fix pylint emacs mode fix classes checkers to handler twisted interfaces 2004 05 14 0 4 1 fix the setup py script to allow bdist_winst well the generated installer has not been tested with the necessary logilab init py file fix file naming convention as suggested by Andreas Amoroso fix stupid crash bug with bad method names 2004 05 10 0 4 0 fix file path with parsable parsable option has been renamed to parseable added patch from Andreas Amoroso to output message to files instead of standard output added Run to the list of correct variable names fix variable names regexp and checking of local classes names some basic handling of metaclasses no docstring rgx apply now on classes too new option to specify a different regexp for methods than for functions do not display the evaluation report when no statements has been analysed fixed crash with a class nested in a method fixed format checker to deals with triple quoted string and lines with code and comment mixed use logilab common ureports to layout reports 2004 02 17 0 3 3 added a parsable text output used when the parsable o
47. eckers respect priority now Close issue 229 Fix a false positive regarding W0511 Closes issue 149 Fix unused import false positive with Python 3 metaclasses 143 Don t warn with bad format character when encountering the a format on Python 3 Add multiple checks for PEP 3101 advanced string formatting bad format string missing format argument key unused format string argument format combined specification missing format attribute and invalid format index Issue broad except and bare except even if the number of except handlers is different than 1 Fixes issue 113 15 1 ChangeLog for Pylint 59 Pylint Documentation Release 1 5 0 Issue attribute defined outside init for all cases not just for the last assignment Closes issue 262 Emit not callable when calling properties Closes issue 268 Fix a false positive with unbalanced iterable unpacking when encountering starred nodes Closes issue 273 Add new checks invalid slice index and invalid sequence index for invalid sequence and slice indices Add assigning non slot warning which detects assignments to attributes not defined in slots Don t emit no name in module for ignored modules Closes issue 223 Fix an unused variable false positive where the variable is assigned through an import Closes issue 196 Definition order is considered for classes function arguments and annotations Closes issue
48. ed some typos set environment variable PYLINT IMPORT to 1 during pylint execution check that variables imported using the global statement exist indentation problems are now warning instead of errors fix checkers initialize to try to load all files with a known python extension patch from wrobell fix a bunch of messages fix sample configuration file fix the bad construction option fix encoding checker fix format checker 2003 09 12 0 2 0 new source encoding FIXME checker pep 263 new zope option which trigger Zope import Useful to check Zope products code new comment option which enable the evaluation note comment disabled by default aton of bug fixes easy functional test infrastructure 2003 06 18 0 1 2 bug fix release remove dependency to pyreverse 2003 06 01 0 1 1 much more functionalities 2003 05 19 0 1 initial release 15 2 Contributors Order doesn t matter not that much at least Sylvain Thenault Logilab main author maintainer Torsten Marek Google maintainer contributor Claudiu Popa maintainer contributor Daniel Balparda Google GPyLint maintainer Google s pylint variant various patches e Martin Pool Google warnings for anomalous backslashes symbolic names for messages like unused etc Alexandre Fayolle Logilab TkInter gui documentation debian support 15 2 Contributors 77 Pylint Documentation Release 1 5 0
49. elds Closes issue 294 Don t emit attribute defined outside init if the attribute was set by a function call in a defining method Closes issue 192 Properly handle unicode format strings for Python 2 Closes issue 296 15 1 ChangeLog for Pylint 57 Pylint Documentation Release 1 5 0 Don t emit mport error if an import was protected by a try except which excepted ImportError Fix an unused import false positive when the error was emitted for all the members imported with from import form Closes issue 304 Don t emit invalid name when assigning a name in an ImportError handler Closes issue 302 Don t count branches from nested functions Fix a false positive with too few format args when the format strings contains duplicate manual position arguments Closes issue 310 fixme regex handles comments without spaces after the hash Closes issue 4311 Don t emit unused import when a special object is imported all doc etc Closes issue 309 Look in the metaclass if defined for members not found in the current class Closes issue 306 Don t emit protected access if the attribute is accessed using a property defined at the class level Detect calls of the parents init through a binded super call Check that a class has an explicitly defined metaclass before emitting old style class for Python 2 Emit catching non exception for non class nodes Closes issu
50. equests Many other people have contributed by their feedback or even patches if I ve forgotten you send me a note Cezar Elnazli deprecated method St phane Wirtel nonlocal without binding Dmitry Pribysh multiple imports not iterable not a mapping various patches Laura Medioni Logilab on behalf of the CNES misplaced comparison constant no classmethod decorator no staticmethod decorator too many nested blocks too many boolean expressions 78 Chapter 15 Changes amp Contributors CHAPTER 16 Content wanted It would be nice to include in the documentation the following information pylint brain project what it is how to install it Please send your pull requests via bitbucket if you can help with the above 79 Pylint Documentation Release 1 5 0 80 Chapter 16 Content wanted Index Symbols argument rgx lt regex gt command line option 20 attr rgx lt regex gt command line option 19 class attribute rgx lt regex gt command line option 20 class rgx lt regex gt command line option 19 const rgx lt regex gt command line option 19 function rgx lt regex gt command line option 19 include naming hint yln command line option 21 inlinevar rgx lt regex gt command line option 20 method rgx lt regex gt command line option 19 module rgx lt regex gt command line option 19 name group lt name name2 gt comm
51. er matters fix 4595 Comma not followed by a space should not occurs on trailing comma in list tuple dict definition fix 22585 Patch fix man warnings for pyreverse 1 manpage fix 20067 AttributeError NoneType object has no attribute name with with 2010 03 01 0 20 0 fix 19498 fix windows batch file fix 19339 pylint el non existing py mod map closes Debian Bug report logs 475939 implement 18860 new W0199 message on assert a b implement 9776 W0150 break or return statement in finally block may swallow exception fix 9263 init and new are checked for unused arguments fix 20991 class scope definitions ignored in a genexpr fix 5975 Abstract intermediate class not recognized as such fix 5977 yield and return statement have their own counters no more R0911 Too many return state ments when a function have many yield stamtements e 99 implement 5564 function method arguments with leading count are ignored in arguments local variables 15 1 ChangeLog for Pylint 67 Pylint Documentation Release 1 5 0 implement 9982 E0711 specific error message when raising NotImplemented remove cache size option 2009 12 18 0 19 0 implement 18947 5561 checker for function arguments include James Lingard string format checker include simple message ids listing by Vincent F rotin 9791 errors only does not hide fatal error anymore include james L
52. erridden methods contributed by sebastianu google com Also inspect arguments to constructor calls and emit relevant warnings contributed by sebas tianu google com Added a new configuration option logging modules to make the list of module names that can be checked for logging not lazy et al configurable contributed by morbo google com ensure init hooks is evaluated before other options notably load plugins 166 Python 2 5 support restored fixed small issues preventing pylint to run on python 2 5 Bitbucket issues 50 and 62 bitbucket 128 pylint doesn t crash when looking for used before assignment in context manager assign ments Add new warning bad reversed sequence for checking that the reversed builtin receive a sequence implements getitem and len without being a dict or a dict subclass or an instance which im plements reversed Mark file as a bad function when using python2 closes 8 Add new warning bad exception context checking that raise from uses a proper exception context None or an exception Enhance the check for used before assignment to look for nonlocal uses Emit undefined all variable if a package s all variable contains a missing submodule closes 126 Add a new warning abstract class instantiated for checking that abstract classes created with abc module and with abstract methods are instantied Do not warn about retur
53. esn t implement enter and exit is used in a with statement e Add a new warning confusing with statement emitted by the base checker when an ambiguous looking with statement is used For example with open as first second which looks like a tuple assignment but is actually 2 context managers 51 Pylint Documentation Release 1 5 0 Add a new warning duplicate except emitted when there is an exception handler which handles an exception type that was handled before Closes issue 485 A couple of warnings got promoted to errors since they could uncover potential bugs in the code These warn ings are assignment from none unbalanced tuple unpacking unpacking non sequence non iterator returned Closes issue 388 Allow ending a pragma control with a semicolon In this way users can continue a pragma control with a reason for why it is used as in pylint disable old style class reason Closes issue 449 jobs can be used with load plugins now Closes issue 456 Improve the performance of jobs when dealing only with a package name Closes issue 479 Don t emit an unused wildcard import when the imported name comes from another module and it is in fact a future name The colorized reporter now works on Windows Closes issue 96 Remove pointless except warning It was previously disabled by default and it wasn t very useful Closes issue 506 Fix a crash on Python 3 related to the s
54. h 2 4 relative import included Robert Kirkpatrick s tutorial and typos fixes fix bug in reenabling message fix 2473 invoking pylint on init py hopefully typecheck acquired members option has been dropped in favor of the more generic generated members option If the zope option is set the behaviour is now to add some default values to generated members flymake integration added bin epylint and elisp pylint flymake el 2008 01 14 0 14 0 fix 3733 Messages dis appear depending on order of file names fix 4026 pylint el should require compile fix a bug in colorized reporter spotted by Dave Borowitz applied patch from Stefan Rank to avoid W0410 false positive when multiple from future import statements implement 4012 flag back tick as deprecated new W0333 message 15 1 ChangeLog for Pylint 69 Pylint Documentation Release 1 5 0 new ignored class option on typecheck checker allowing to skip members checking based on class name patch provided by Thomas W Barr 2007 06 07 0 13 2 fix disable checker option so that it won t accidentally enable the rpython checker which is disabled by default added note about the gedit plugin into documentation 2007 03 02 0 13 1 fix some unexplained 0 13 0 packaging issue which led to a bunch of files missing from the distribution 2007 02 28 0 13 0 new RPython Restricted Python checker for PyPy fellow or people wanting to get a compiled version
55. hapter 2 Running Pylint Pylint Documentation Release 1 5 0 list msgs Generate pylint s messages full documentation Generate pylint s full documentation in reST format 2 3 Parallel execution It is possible to speed up the execution of Pylint If the running computer has more CPUs than one then the files to be checked could be spread on all processors to Pylint sub processes This functionality is exposed via 3 command line parameter It takes a number of sub processes that should be spawned If the provided number is 0 then the number of CPUs will be used The default number of workers is 1 Example pylint j 4 mymodulel py mymodule2 py mymodule3 py mymodule4 py This will spawn 4 parallel Pylint sub process where each provided module will be checked in parallel Discovered problems by checkers are not displayed immediately They are shown just after completing checking a module There are some limitations in running checks in parallel in current implementation It is not possible to use custom plugins Le load plugins option nor it is not possible to use initialization hooks i e init hook option 2 3 Parallel execution 7 Pylint Documentation Release 1 5 0 8 Chapter 2 Running Pylint CHAPTER 3 Pylint output The default format for the output is raw text You can change this by passing pylint the output format value option Possible values are parseable colo
56. he number an severity of the warnings and errors This has proven to be very motivating for some programmers Pylint was born in 2003 at Logilab that funded Sylvain Th nault to lead its development up to now 1 2 What Pylint is not What Pylint says is not to be taken as gospel and Pylint isn t smarter than you are it may warn you about things that you have conscientiously done Pylint tries hard to report as few false positives as possible for errors but it may be too verbose with warnings That s for example because it tries to detect things that may be dangerous in a context but are not in others or because it checks for some things that you don t care about Generally you shouldn t expect Pylint to be totally quiet about your code so don t necessarily be alarmed if it gives you a hell lot of messages for your project Quoting Alexandre Fayolle My usage pattern for Pylint is to generally run pylint E quite often to get stupid errors flagged before launching an application or before committing I generally run Pylint with all the bells and whistles activated some time before a release when I want to cleanup the code And when I do that I simply ignore tons of the false warnings and I can do that without being driven mad by this dumb program which is not smart enough to understand the dynamicity of Python because I only run it once or twice a week in this mode Quoting Marteen Ter Huurne In our project we just accepted that we have
57. his behavior set the option accept no param doc to yes in your pylintrc 5 1 Parameter documentation checker 17 Pylint Documentation Release 1 5 0 18 Chapter 5 Optional Pylint checkers in the extensions module CHAPTER 6 Configuration 6 1 Naming Styles Pylint recognizes a number of different name types internally With a few exceptions the type of the name is governed by the location the assignment to a name is found in and not the type of object assigned module Module and package names same as the file names const Module level constants any variable defined at module level that is not bound to a class object class Names in class statements as well as names bound to class objects at module level function Functions toplevel or nested in functions or methods method Methods functions defined in class bodies Includes static and class methods attr Attributes created on class instances inside methods argument Arguments to any function type including lambdas variable Local variables in function scopes class attribute Attributes defined in class bodies inlinevar Loop variables in list comprehensions and generator expressions For each naming style a separate regular expression matching valid names of this type can be defined By default the regular expressions will enforce PEP8 names Regular expressions for the names are anchored at the beginning any anchor for the end must be supplied ex
58. ilable in Gentoo Fedora 4 Ubuntu FreeBSD Darwin and maybe others if you know about more OSes please drop us a note 14 3 Python packages Pylint should be easily installable using setuptools and the Python Package Index Try easy install or pip depending on your preference 14 4 Source distribution installation From the source distribution extract the tarball go to the extracted directory and simply run python setup py install You ll have to install dependencies in a similar way Windows users may get valuable information about Pylint installation on this page 49 Pylint Documentation Release 1 5 0 14 5 Note for Windows users On Windows once you have installed Pylint the command line usage is pylint bat options module or package But this will only work if pylint bat is either in the current directory or on your system path setup py will install python bat to the Scripts subdirectory of your Python installation e g C Python24Scripts You can do any of the following to solve this 1 Change to the appropriate directory before running pylint bat 2 Add the Scripts directory to your path statement in your autoexec bat file this file is found in the root directory of your boot drive 3 Create a redirect batch file in a directory actually on your systems path To effect 2 simply append the appropriate directory name to the PATH statement in autoexec bat Be su
59. in the following order and uses the first one it finds 1 pylintrc in the current working directory 2 pylintrc in the current working directory 3 If the current working directory is in a Python module Pylint searches up the hierarchy of Python modules until itfinds a pylintrc file This allows you to specify coding standards on a module by module basis Of course a directory is judged to be a Python module if it contains an init__ py file 4 The file named by environment variable PYLINTRC 5 if you have a home directory which isn t root a pylintrc in your home directory b config pylintrc in your home directory 6 etc pylintrc The generate rcfile option will generate a commented configuration file on standard output according to the current configuration and exit This includes Any configuration file found as explained above Options appearing before generate rcfile on the Pylint command line Of course you can also start with the default values and hand tune the configuration Other useful global options include ignore lt file file gt Add lt file gt may be a directory to the black list It should be a base name not a path Multiple entries can be given separated by comma persistentzy or n Pickle collected data for later comparisons output format lt format gt Select output format text html custom msg template lt template gt Modifiy text output message template 6 C
60. ingard patches for and duplicate key in dicts include James Lingard patches for function call arguments checker improved flymake code and doc provided by Derek Harland refactor and fix the imports checker fix 18862 E0601 false positive with lambda functions fix 8764 More than one statement on a single line false positive with try except finally fix 9215 false undefined variable error in lambda function fix for w0108 false positive Nathaniel fix test fulltest sh 5821 added a utility function to run pylint in another process patch provide by Vincent F rotin 2009 03 25 0 18 0 tests ok with python 2 4 2 5 2 6 2 3 not tested fix 8687 W0613 false positive on inner function fix 8350 C0322 false positive on multi line string fix 8332 set E0501 line no to the first line where non ascii character has been found avoid some E0203 E0602 false negatives by detecting respectively AttributeError NameError implements 4037 don t issue W0142 or magic when they are barely passed from arguments complete 5573 more complete list of special methods also skip W0613 for python internal method don t show information messages by default integration of Yuen Ho Wong s patches on emacs lisp files 2009 03 19 0 17 0 semicolon check move W0601 to W0301 remove rpython remove all rpython checker modules and tests astng 0 18 compatibility support for ast module modifies interfaces 2009 01 28 0 16 0
61. ion expression doesn t support subscription i e doesn t define __getitem__ method Don t warn about abstract classes instantiated in their own body Closes issue 627 Obsolete options are not present by default in the generated configuration file Closes issue 632 non iterator returned can detect classes with iterator metaclasses Closes issue 679 Add a new error unsupported membership test emitted when value to the right of the in operator doesn t support membership test protocol i e doesn t define contains iter getitem e Add new errors not an iterable emitted when non iterable value is used in an iterating context starargs for statement comprehensions etc and not a mapping emitted when non mapping value is used in a mapping context Closes issue 563 Make no self use checker not emit a warning if there is a super call inside the method Closes issue 667 Add checker to identify multiple imports on one line Closes issue 598 e Fix unused argument false positive when the operator is used Closes issue 518 Don t emit import error for ignored modules PyLint will not emit import errors for any import which is or is a subpackage of a module in the ignored modules list Closes issue 223 Fix unused import false positive when the import is used in a class assignment Closes issue 475 e Add a new error not context manager emitted when something that do
62. irectory export PYTHONPATH src You now have access to the astroid logilab common and pylint packages without installing them You can run all the unit tests like so cd src pylint test for f in py do echo f python S f done The S flag keeps distutils from interfering with sys path YMMV 10 5 Adding new functional tests Pylint comes with an easy way to write functional tests for new checks e put a Python file in the test input directory whose name starts with func and should also contains the symbolic name of the tested check e add the expected message file in the test messages directory using the same name but a txt extension instead of PY 32 Chapter 10 Contribute Pylint Documentation Release 1 5 0 The message file should use the default text output format without reports and lines should be sorted E g on Unix system you may generate it using pylint rn input func mycheck py sort pylint messages func mycheck txt Also here are a few naming convention which are used e Python files starting with func_noerror don t have any message file associated as they are expected to provide no output at all You may provide different input files and associated output depending on the Python interpreter version tests whose name ends with _py lt xy gt py are used for Python gt x y tests whose name ends with _py lt _xy gt py are used for Python
63. leon You can activate this checker by adding the line load plugins pylint extensions check docs to the MASTER section of your pylintrc This checker verifies that all function method and constructor parameters are mentioned in the Sphinx param and type parts of the docstring def function foo x y z PIU PUNCELON foo sas param x bla x type x int param y bla y type y float param int z bla z return sum rtype float paw return x y z or the Google style Args part of the docstring def function foo x y z UU functqon LOO ses ACS x int s Dla x y float bla y z int bla z 15 Pylint Documentation Release 1 5 0 Returns float sum pad return x y z orthe Numpy style Parameters part of the docstring def function foo x y z rtfunction foo Parameters xv Ant bla x y float bla y ze Ine bla z Returns float sum return x y z You ll be notified of missing parameter documentation but also of naming inconsistencies between the signature and the documentation which often arise when parameters are renamed automatically in the code but not in the documentation By convention constructor parameters are documented in the class docstring __init__ and new methods are considered constructors class ClassFoo object Sphinx style docstring foo param float
64. loses issue 297 ignored modules can work with qualified names as well as with Unix pattern matching for recursive ignoring Closes issues 244 Improve detection of relative imports in non packages as well as importing missing modules with a relative import from a package Don t emit no init if not all the bases from a class are known Closes issue 604 no space check option accepts empty line as a possible option Closes issue 541 generate rcfile generates by default human readable symbols for the disable option Closes issue 608 Improved the not in loop checker to properly detect more cases Add a new error continue in finally which is emitted when the continue keyword is found inside a finally clause which is a SyntaxError The zope flag is deprecated and it is slated for removal in Pylint 1 6 The reason behind this removal is the fact that it s a specialized flag and there are solutions for the original prob lem use generated members with the members that causes problems when using Zope or add AST transforms tailored to the zope project At the same time include ids and symbols will also be removed in Pylint 1 6 Closes issue 570 missing module attribute was removed and the corresponding CLI option required attributes which is slated for removal in Pylint 1 6 missing reversed argument was removed The reason behind this is that this kind of errors should be detected by the type checker
65. mber of messages with the following format MESSAGE TYPE LINE NUM OBJECT MESSAGE You can get another output format useful since it s recognized by most editors or other development tools using the output format parseable option The message type can be R C efactor for a good practice metric violation c onvention for coding standard violation W arning for stylistic problems or minor programming issues E rror for important programming issues i e most probably bug e Flatal for errors which prevented further processing Sometimes the line of code which caused the error is displayed with a caret pointing to the error This may be generalized in future versions of Pylint Example extracted from a run of Pylint on itself kx x x x Module pylint checkers format W 50 Too long line 86 80 W 108 Operator not followed by a space print gt gt sys stderr Unable to match r line 141 Too long line 81 80 74 searchall Unreachable code 171 FormatChecker process tokens Redefining built in type 150 FormatChecker process tokens Too many local variables 20 15 150 FormatChecker process tokens Too many branches 13 12 23323333 3 2 Reports section Following the analysis message Pylint will display a set of reports each one focusing on a particular aspect of the project such as number of messages by categories module
66. more connected to the last analyzed module close 10106 fix some bugs related to local disabling of messages fix cr lf pb when generating the rc file on windows platforms 2006 04 19 0 11 0 fix crash caused by the exceptions checker in some case fix some E1101 false positive with abstract method or classes defining getattr dirty fix to avoid socketobject has not connect member The actual problem is that astng isn t able to understand the code used to create socket socket object with exec added an option in the similarity checker to ignore docstrings enabled by default included patch from Benjamin Niemann to allow block level enabling disabling of messages 2006 03 06 0 10 0 WARNING this release include some configuration changes see below so you may have to check and update your own configuration file s if you use one this release require the 0 15 version of astng or superior it will save you a lot of pylint crashes W0705 has been reclassified to E0701 and is now detecting more inheriting problem and a false positive when empty except clause is following an Exception catch has been fixed close 10422 E0212 and E0214 metaclass class method should have mcs cls as first argument have been reclassified to C0202 and C0203 since this not as well established as self for instance method E0213 W02724 has been reclassified into F0220 failed to resolve interfaces implemented by a class a new t
67. mp Contributors 15 1 ChangeLog forPyhnt use Rx EXE A nee ead ea RUE OS key OX YU S 15 2 Contributors 4 272 4 Dl he oe ue uu esie Aum de Ea Se te Ea ae qe dum qai S Content wanted 35 35 35 36 39 41 41 41 42 43 44 44 47 51 51 77 79 Pylint Documentation Release 1 5 0 Pylint s home page is at http www pylint org and its forge is at https bitbucket org logilab pylint Contents 1 Pylint Documentation Release 1 5 0 2 Contents CHAPTER 1 Introduction 1 1 What is Pylint Pylint is a tool that checks for errors in Python code tries to enforce a coding standard and looks for bad code smells This is similar but nevertheless different from what pychecker provides especially since pychecker explicitly does not bother with coding style The default coding style used by Pylint is close to PEP 008 aka Guido s style guide For more information about code smells refer to Martin Fowler s refactoring book Pylint will display a number of messages as it analyzes the code as well as some statistics about the number of warnings and errors found in different files The messages are classified under various categories such as errors and warnings more below If you run Pylint twice it will display the statistics from the previous run together with the ones from the current run so that you can see if the code has improved or not Last but not least the code is given an overall mark based on t
68. mpatible with both versions and from this benefits not only the maintainers but the end users as well because it s easier to add and test new features If support for Python 2 6 is absolutely required then the version from pylint 1 3 branch can be used It will receive backports of bug fixes for a while 12 3 3 Running Pylint 12 3 1 3 1 Can I give pylint a file as an argument instead of a module Pylint expects the name of a package or module as its argument As a convenience you can give it a file name if it s possible to guess a module name from the file s path using the python path Some examples pylint mymodule py should always work since the current working directory is automatically added on top of the python path pylint directory mymodule py will work if directory is a python package i e has an init py file or if direc tory is in the python path pylint whatever directory mymodule py will work if either whatever directory is in the python path your cwd is whatever directory directory is a python package and whatever is in the python path directory is a python package and your cwd is whatever and so on 12 3 2 3 2 Where is the persistent data stored to compare between successive runs Analysis data are stored as a pickle file in a directory which is localized using the following rules value of the PYLINTHOME environment variable if set p
69. n arg in generator in Python 3 34 Do not warn about abstract method when the abstract method is implemented through assignment 155 Improve cyclic import detection in the case of packages patch by Buck Golemon Add new warnings for checking proper class slots invalid slots object and invalid slots Search for rc file in config pylintrc if pylintrc doesn t exists 121 Don t register the newstyle checker w python gt 3 Fix unused import false positive w augment assignment 78 Fix access member before definition false negative wrt aug assign 164 Do not attempt to analyze non python file eg so file 122 2013 12 22 1 1 0 Add new check for use of deprecated pragma directives pylint disable msg or pylint enable msg 10022 deprecated pragma which was previously emmited as a regular warn e Avoid false used before assignment for except handler defined identifier used on the same line 111 15 1 ChangeLog for Pylint 61 Pylint Documentation Release 1 5 0 Combine no space after operator no space after comma and no space before operator into a new warning bad whitespace Add a new warning superfluous parens for unnecessary parentheses after certain keywords Fix a potential crash in the redefine in handler warning if the redefined name is a nested getattr node Add a new option for the multi statement warning to allow single line if statements Add ba
70. nstead Warn when assigning to __metaclass__ at a class scope in Python 3 a metaclass is specified as an argument to the class statement Warn when performing parameter tuple unpacking it is not supported in Python 3 abstract class instantiated is also emitted for Python 2 It was previously disabled Add long suffix error emitted when encountering the long suffix on numbers Add support for disabling a checker by specifying an enabled attribute on the checker class Add a new CLI option py3k for enabling Python 3 porting mode This mode will disable all other checkers and will emit warnings and errors for constructs which are invalid or removed in Python 3 Add old octal literal to Python 3 porting checker emitted when encountering octals with the old syntax Add implicit map evaluation to Python 3 porting checker emitted when encountering the use of map builtin without explicit evaluation 2014 07 26 1 3 0 Allow hanging continued indentation for implicitly concatenated strings Closes issue 232 Pylint works under Python 2 5 again and its test suite passes Fix some false positives for the cellvar from loop warnings Closes issue 233 Return new astroid class nodes when the inferencer can detect that that result of a function invocation on a type like type or abc ABCMeta is requested Closes 205 Emit undefined variable for undefined names when using the Python 3 metaclass argument Ch
71. of logging and string format checkers have been changed logging 65 gt 12 string format 99 gt 13 Also add documentation to say that ids of range 1 50 shall be reserved to pylint internal checkers 69993 Additional string format checks for logging module check for missing arguments too many arguments or invalid string formats in the logging checker module Contributed by Daniel Arena 09220 add column offset to the reports If you ve a custom reporter this change may break it has now location gain a new item giving the column offset 60828 Fix false positive in reimport check 70495 absolute imports fail depending on module path patch by Jacek Konieczny 22273 Fix ignore option documentation to match reality 2011 01 11 0 23 0 documentation update add manpages several performance improvements finalize python3 support new W0106 warning Expression s is assigned to nothing drop E0501 and E0502 messages about wrong source encoding not anymore interesting since it s a syntax error for python gt 2 5 and we now only support this python version and above don t emit W0221 or W0222 when methods as variable arguments eg arg and or args Patch submitted by Charles Duffy 2010 11 15 0 22 0 python versions minimal python3 x support drop python 2 5 support 2010 10 27 0 21 4 fix 48066 pylint crashes when redirecting output containing non ascii characters fix 19799 pylint
72. or instance a b is fine a b c crash 88914 fix parsing of generated members options leading to crash when using a regexp value set fix potential crashes with utils safe infer raising InferenceError 2011 12 08 0 25 1 81078 Warn if names in exception handlers clobber overwrite existing names patch by tmarek google com 15 1 ChangeLog for Pylint 65 Pylint Documentation Release 1 5 0 81113 Fix W0702 messages appearing with the wrong line number patch by tmarek google com 50461 52020 51222 Do not issue warnings when using 2 6 s property setter deleter functionality patch by dneil O google com 9188 4024 Do not trigger W0631 if a loop variable is assigned in the else branch of a for loop 2011 10 07 0 25 0 1774742 make allowed name for first argument of class method configurable patch by Google 74087 handle case where inference of a module return YES this avoid some cases of TypeError Yes object does not support indexing patch by Google 74745 make too general exception names configurable patch by Google 74747 crash occurs when lookup up a special attribute in class scope patch by google 76920 crash if on eg pylint refile patch by Torsten Marek 77237 warning for E0202 may be very misleading 73941 HTML report messages table is badly rendered 2011 07 18 0 24 0 09738 add regular expressions support for generated members ids
73. ost command hook show fly err at point Alternative if you only wish to pollute the minibuffer after an explicit flymake goto then use the following instead of a post command hook defadvice flymake goto next error after display message activate compile Display the error in the mini buffer rather than having to mouse over it show fly err at point defadvice flymake goto prev error after display message activate compile Display the error in the mini buffer rather than having to mouse over it show fly err at point 26 Chapter 8 Editor and IDE integration rror messages Pylint Documentation Release 1 5 0 8 2 Setup the MS Visual Studio NET 2003 editor to call Pylint External Tools xj Menu Contents Activex Control Test Co amp ntainer Add Error Loo amp kup ATL MFC amp Trace Tool Delete OLE COM Object amp Viewer Spy amp Create amp GUID Move Up Move Down Title Pylint Command Jes bn Python23 Scripts pylint bat et Arguments itemDir ItemFileName ItemExt El Initial directory Lo Sa S 5 5 4 2 PyChecker2 v Use Output window Prompt for arguments V Close on exit The output of Pylint is then shown in the Output pane of the editor 8 3 Integrate Pylint with TextMate Install Pylint in the usual way pip install pylint Install the Python bundle for TextMate 1 select TextMate gt Preferences 2 sele
74. plicitly Any name not matching the regular expression will lead to an instance of invalid name module rgx lt regex gt Default value a z_ a 20 9 1 2 30 const rgx regex Default value a z lla z0 9 1 2 30 class rgx regex Default value JA Z a zA 20 9 function rgx regex Default value a z a z0 9 1 2 30 5 method rgx lt regex gt Default value a z_ a z0 9_ 2 30 19 Pylint Documentation Release 1 5 0 attr rgx regex Default value a z a z0 9 1 2 30 argument rgx lt regex gt Default value a z a z0 9 1 2 30 variable rgx regex Default value a z a z0 9 1 2 30 class attribute rgx regex Default value A Za z_ A Za z0 9_ 2 30 __ __ inlinevar rgx regex Default value A Za z A Za z0 9 6 1 1 Multiple Naming Styles Large code bases that have been worked on for multiple years often exhibit an evolution in style as well In some cases modules can be in the same package but still have different naming style based on the stratum they belong to However intra module consistency should still be required to make changes inside a single file easier For this case Pylint supports regular expression with several named capturing group Rather than emitting name warnings immediately Pylint will determine the prevalent naming style inside each module and enforce it on all names
75. protocol false positive for read only containers like tuple bitbucket 16 fix False positive E1003 on Python 3 for argument less super bitbucket 6 put back documentation in source distribution bitbucket 15 epylint shouldn t hang anymore when there is a large output on pylint stderr bitbucket 7 fix epylint w python3 bitbucket 3 remove string module from the default list of deprecated modules 2013 04 25 0 28 0 bitbucket 1 fix dictionary changed size during iteration crash e 74013 new E1310 bad str strip call message warning when a call to a Lr strip method contains du plicate characters patch by Torsten Marek e 123233 new E0108 duplicate argument name message reporting duplicate argument names 15 1 ChangeLog for Pylint 63 Pylint Documentation Release 1 5 0 81378 emit WO120 useless else on loop for loops without break 124660 internal dependencies should not appear in external dependencies report 124662 fix name error causing crash when symbols are included in output messages 123285 apply pragmas for warnings attached to lines to physical source code lines 123259 do not emit E0105 for yield expressions inside lambdas 123892 don t crash when attempting to show source code line that can t be encoded with the current locale settings Simplify checks for dangerous default values by unifying tests for all different mutable compound literals Improve the description for E1124
76. ption is provided added an emacs mode using this output available in the distrib s elisp directory fixed some typos in messages change include ids options to yn and allow it to be in the configuration file 15 1 ChangeLog for Pylint 75 Pylint Documentation Release 1 5 0 do not chock on corrupted stats files fixed bug in the format checker which may stop pylint execution provide scripts for unix and windows to wrap the minimal pylint tk gui 2003 12 23 0 3 2 e html escape messages in the HTML reporter bug reported by Juergen Hermann added TODO to the list of default note tags added rexec to the list of default deprecated modules fixed typos in some messages 2003 12 05 0 3 1 bug fix in format and classes checkers remove print statement from imports checkers provide a simple tk gui essentially useful for windows users 2003 11 20 0 3 0 new exceptions checker checking for string exception and empty except clauses imports checker checks for reimport of modules classes checker checks for calls to ancestors _ init and abstract method not overridden It doesn t complain anymore for unused import in __init__ files and provides a new option ignore interface methods useful when you re using zope Interface implementation in your project base checker checks for black listed builtins call controled by the bad functions option and for use of and format checker checks for use
77. r much probably bugs in the code F fatal if an error occurred which prevented pylint from doing further processing When Pylint is first run on a fresh piece of code a common complaint is that it is too noisy The current default configuration is set to enforce all possible warnings We ll use some of the options I noted above to make it suit your preferences a bit better and thus make it scream only when needed 11 3 Your First Pylint ing We ll use a basic python script as fodder for our tutorial I borrowed extensively from the code here http www daniweb com code snippet748 html The starting code we will use is called simplecaeser py and is here in its entirety 1 usr bin env python 2 3 import string 4 5 shift 3 6 choice raw input would you like to encode or decode 7 word raw input Please enter text 8 letters string ascii letters string punctuation string digits 9 encoded 10 if choice encode 11 for letter in word 12 if letter ES ncoded encoded 14 else 15 x letters index letter shift 16 ncoded encoded letters x 17 if choice decode 18 for letter in word 19 if letter 20 ncoded encoded 36 Chapter 11 A Beginner s Guide to Code Standards in Python Pylint Tutorial Pylint Documentation Release 1 5 0 21 else 22 x letters index letter shift 23 ncoded encoded lette
78. re to use the Windows directory separator of between entries Then once you have rebooted this is necessary so that the new path statement will take effect when autoexec bat is run you will be able to invoke Pylint with pylint bat on the command line 3 is the best solution Once done you can call Pylint at the command line without the bat just as do non Windows users by typing pylint options module or package To effect option 3 simply create a plain text file pylint bat with the single line C PythonDirectory Scripts pylint bat where PythonDirectory is replaced by the actual Python installation directory on your system e g C Python24Scriptspylint bat 50 Chapier 14 Installation CHAPTER 15 Changes amp Contributors 15 1 ChangeLog for Pylint Added a new refactoring warning too many boolean expressions used when a if statement contains too many boolean expressions which makes the code less maintainable and harder to understand Closes issue 677 Property methods are shown as attributes instead of functions in pyreverse class diagrams Closes Issue 284 Add a new refactoring error too many nested blocks which is emitted when a function or a method has too many nested blocks which makes the code less readable and harder to understand Closes issue 668 Add a new error unsubscriptable object that is emitted when value used in subscript
79. redundant key word arg 2013 02 26 0 27 0 20693 replace pylint el by Ian Eure version patch by J Kotta 105327 add support for disable all option and deprecate the disable all inline directive in favour of skip file patch by A Fayolle 110840 add messages 10020 and 10021 for reporting of suppressed messages and useless suppression pragmas patch by Torsten Marek 112728 add warning E0604 for non string objects in all patch by Torsten Marek 120657 add warning WOI 10 deprecated lambda when a map filter of a lambda could be a comprehen sion patch by Martin Pool 113231 logging checker now looks at instances of Logger classes in addition to the base logging module patch by Mike Bryant 111799 don t warn about octal escape sequence but warn about o which is not octal in Python patch by Martin Pool 110839 bind F5 to Run button in pylint gui 115580 fix erroneous W0212 access to protected member on super call patch by Martin Pool 110853 fix a crash when an init method in a base class has been created by assignment rather than direct function definition patch by Torsten Marek 110838 fix pylint gui crash when include ids is activated patch by Omega Weapon 112667 fix emission of reimport warnings for mixed imports and extend the testcase patch by Torsten Marek 112698 fix crash related to non inferable all attributes and invalid all contents patch by Torsten Marek
80. riables used as default arguments to function where the variable was first defined in the class scope Closes issue 342 and issue 404 Add a new warning unexpected special method signature which is emitted when a special method dunder method doesn t have the expected signature which can lead to actual errors in the application code Closes issue 253 e Remove bad context manager due to the inclusion of unexpected special method signature Don t emit no name in module if the import is guarded by an ImportError Exception or a bare except clause Don t emit no member if the attribute access node is protected by an except handler which handles AttributeEr ror Exception or it is a bare except Don t emit import error if the import is guarded by an ImportError Exception or a bare except clause Don t emit undefined variable if the node is guarded by a NameError Exception or bare except clause Add a new warning using constant test which is emitted when a conditional statement If IfExp uses a test which is always constant such as numbers classes functions etc This is most likely an error from the user s part Closes issue 524 Don t emit raising non exception when the exception has unknown bases We don t know what those bases actually are and it s better to assume that the user knows what he is doing rather than emitting a message which can be considered a false positive Look for
81. rized msvs visual studio and html Moreover you can customize the exact way information are displayed using the msg template format string option The format string uses the Python new format syntax and the following fields are available path relative path to the file abspath absolute path to the file line line number column column number module module name obj object within the module if any msg text of the message msg id the message code eg 10011 symbol symbolic name of the message eg locally disabled C one letter indication of the message category category fullname of the message category For example the former pre 1 0 default format can be obtained with pylint msg template msg_id line 3d column obj msg A few other examples the new default format C line 3d column 2d msg symbol Visual Studio compatible format former msvs output format path line msg_id obj msg Parseable Emacs and all former parseable output format format path line msg_id symbol obj msg HTML output Default for the html output format format Pylint Documentation Release 1 5 0 category module obj line column msg 3 1 Source code analysis section For each python module Pylint will first display a few characters followed by the name of the module Then a nu
82. rning means that future versions of Python may not support that code so my code may break in the future There are 5 invalid name messages that we will get to later Lastly I violated the convention of using spaces around an operator such as so I ll fix that too To sum up lll add a docstring to line 2 put spaces around the sign on line 16 and use the disable deprecated module to ignore the deprecation warning Here is the updated code 1 usr bin env python 2 This script prompts a user to enter a message to encode or decode 3 using a classic Caeser shift substitution 3 letter shift 4 5 import string 6 7 shift 3 8 choice raw_input would you like to encode or decode 9 word raw_input Please enter text 10 letters string ascii_letters string punctuation string digits 11 encoded 12 if choice encode 11 4 The Next Step 39 Pylint Documentation Release 1 5 0 13 for letter in word 14 if letter 15 ncoded encoded 16 else 17 x letters index letter shift 18 ncoded encoded letters x 19 if choice decode 20 for letter in word 21 if letter 22 ncoded encoded 23 else 24 x letters index letter shift 25 ncoded encoded letters x 26 27 print encoded And here is what happens when we run it with our disable deprecated module option rober
83. rs x 24 25 print encoded Let s get started If we run this d modul robertk01 Desktop pylint simplecaeser py No config file found using default configuration xxxxxxxxxxxx x Module simplecaeser C 1 0 Missing module docstring missing docstring W 3 0 Uses of a deprecated module string deprecat Cs 5 0 Invalid constant name shift invalid name C 6 0 Invalid constant name choice invalid name as 7 0 Invalid constant name word invalid name ce 8 0 Invalid constant name letters invalid name Ct 9 0 Invalid constant name encoded invalid name C 16 12 Operator not preceded by a space ncoded encoded letters x no space before operator Report 19 statements analysed Duplication now previous difference nb duplicated lines 0 0 percent duplicated lines 0 000 0 000 Raw metrics type number previous difference code 21 87 50 21 docstring 0 0 00 0 comment 1 4 17 1 empty 2 8 33 2 11 3 Your First Pylint ing 37 Pylint Documentation Release 1 5 0 Statistics by type t type number old number difference documented badname ES de le T module I al 0 00 0 00 E Es ta ak S class 0 0 0 00 0 00 method 0 0 0 00 0 00 function 0 0 0 00 0 00 le de E m
84. rstudio org mercurial eXe http exelearning org PrimaGIS http www primagis org python cdd https projetos ossystems com br projects python cdd CDSWare http cdsware cern ch ASE http dewww camp dtu dk campos ASE intro html RunJob http projects fnal gov runjob Slugathon http slugathon python hosting com Topographica http topographica org Home index html at least they intend to do so http browsershots org many more Also notice that the CheeseCake kwalitee reporting tool uses Pylint to analyze the source code 47 Pylint Documentation Release 1 5 0 48 Chapter 13 Some projects using Pylint CHAPTER 14 Installation 14 1 Dependencies Pylint requires the latest astroid and logilab common packages It should be compatible with any Python version gt 2 1 14 2 Distributions The source tarball is available at http download logilab org pub pylint You may apt get a well tested Debian or Ubuntu package by adding one of these lines deb http download logilab org production unstable deb http download logilab org production sid deb http download logilab org production squeeze deb http download logilab org production lenny to your etc apt sources list file Pylint is also available in the standard Debian distribution but add our public debian repository anyway if you want to get the latest releases and upgrades earlier Pylint is also ava
85. s dependencies For instance the metrics report displays summaries gathered from the current run the number of processed modules for each module the percentage of errors and warnings the total number of errors and warnings percentage of classes functions and modules with docstrings and a comparison from the previous run percentage of classes functions and modules with correct name according to the coding standard and a com parison from the previous run e a list of external dependencies found in the code and where they appear 10 Chapter 3 Pylint output Pylint Documentation Release 1 5 0 Also a global evaluation for the code is computed 3 2 Reports section 11 Pylint Documentation Release 1 5 0 12 Chapter 3 Pylint output CHAPTER 4 Messages control An example available from the examples directory bylint option block disable revision None class Foo object block disable test def _ init self def def def def def pass methl self arg this issues a message print self meth2 self arg and this one noten pylint disable unused argument print self ioe meth3 self test one line disabling no error print self bla pylint disable no member error print self blop meth4 self test re enabling pylint disable no member no error print self bla print self blop
86. sion a z versus A Z If we run that rule using a const rex a z a z0 9 2 30 option it will now be quite quiet robertk01 Desktop pylint reports n disable deprecated modul No config file found using default configuration const rgx ba sz lay Regular expressions can be quite a beast so take my word on this particular example but go ahead and read up on them if you want Tip It would really be a pain in the butt to have to use all these options on the command line all the time That s what the rc file is for We can configure our Pylint to store our options for us so we don t have to declare them on the command line Using the rc file is a nice way of formalizing your rules and quickly sharing them with others Invoking pylint generate rcfile will create a sample rcfile with all the options set and explained in comments That s it for the basic intro More tutorials will follow 40 Chapter 11 A Beginner s Guide to Code Standards in Python Pylint Tutorial z0 9 425 30 CHAPTER 12 Frequently Asked Questions 12 1 1 About Pylint 12 1 1 1 1 What is Pylint Pylint is a static code checker meaning it can analyse your code without actually running it Pylint checks for errors tries to enforce a coding standard and tries to enforce a coding style 12 1 2 1 2 How is Pylint different from Pychecker A major difference between Pylint and Pychecker is that Pylint
87. t allow both const and variable names New warning trailing whitespace C0303 that warns about trailing whitespace Added a new warning unpacking in except W0712 about unpacking exceptions in handlers which is unsupported in Python 3 Add a configuration option for missing docstring to optionally exempt short functions methods classes from the check Add the type of the offending node to missing docstring and empty docstring New utility classes for per checker unittests in testutils py Do not warn about redefinitions of variables that match the dummy regex Do not treat all variables starting with _ as dummy variables only _ itself Make the line too long warning configurable by adding a regex for lines for with the length limit should not be enforced Do not warn about a long line if a pylint disable option brings it above the length limit Do not flag names in nested with statements as undefined Added a new warning old raise syntax for the deprecated syntax raise Exception args Support for PEP 3102 and new missing kwoa E1125 message for missing mandatory keyword argument logilab org s 107788 Fix spelling of max branchs option now max branches Added a new base class and interface for checkers that work on the tokens rather than the syntax and only tokenize the input file once Follow astng renaming to astroid bitbucket 37 check for unbalanced unpacking in assignments bitbucket 25 fix incomplete
88. tand what rule I violated Knowing only that I violated a convention isn t much help if Pm a newbie Another information there is the message symbol between parens missing docstring here If I want to read up a bit more about that I can go back to the command line and try this robertk01 Desktop pylint help msg missing docstring No config file found using default configuration missing docstring C0111 Missing docstringx Used when a module function class or method has no docstring Some special methods like _ init doesn t necessary require a docstring This message belongs to the basic checker Yeah ok That one was a bit of a no brainer but I have run into error messages that left me with no clue about what went wrong simply because I was unfamiliar with the underlying mechanism of code theory One error that puzzled my newbie mind was o too many instance attributes R0902 Too many instance attributes s s I get it now thanks to Pylint pointing it out to me If you don t get that one pour a fresh cup of coffee and look into it let your programmer mind grow 11 4 The Next Step Now that we got some configuration stuff out of the way let s see what we can do with the remaining warnings If we add a docstring to describe what the code is meant to do that will help I m also going to be a bit cowboy and ignore the deprecated module message because I like to take risks in life A deprecation wa
89. test func 10010 new message E0103 for break or continue outside loop close 8883 test func continue not in loop fix bug in the variables checker causing non detection of some actual name error close 8884 test func nameerror on string substitution fix bug in the classes checker which was making pylint crash if object is assigned in a class inheriting from it test func noerror object as class attribute fix problem with the similar checker when related options are defined in a configuration file new generate man option to generate pylint s man page require the latest logilab common gt 0 9 3 packaged generated man page 2005 02 24 0 6 3 fix scope problem which may cause false positive and true negative on E0602 fix problem with some options such as disable msg causing error when they are coming from the configu ration file 2005 02 16 0 6 2 fix false positive on E0201 access to undefined member with metaclasses fix false positive on E0203 access to member before its definition when attributes are defined in a parent class fix false positive on W0706 identifier used to raise an exception assigned to TE t e fix interpretation of t as value for the indent string configuration variable fix refile so that rcfile pylintre only refile pylintrc was working in earlier release new raw checker example in the examples directory 2005 02 04 0 6 1
90. tk01 Desktop pylint reports n disable deprecated modul No config file found using default configuration xxxxxxxxxxxx x Module simplecaeser Es 7 0 Invalid constant name shift invalid name C 8 0 Invalid constant name choice invalid name Ce 9 0 Invalid constant name word invalid name C 10 0 Invalid constant name letters invalid name C 11 0 Invalid constant name encoded invalid name simplecaeser py Nice We re down to just the invalid name messages There are fairly well defined conventions around naming things like instance variables functions classes etc The conventions focus on the use of UPPERCASE and lowercase as well as the characters that separate multiple words in the name This lends itself well to checking via a regular expression thus the should match A Z_ A Z1 A e In this case Pylint is telling me that those variables appear to be constants and should be all UPPERCASE This rule is in fact a naming convention that is specific to the folks at Logilab who created Pylint That is the way they have chosen to name those variables You too can create your own in house naming conventions but for the purpose of this tutorial we want to stick to the PEP 8 standard In this case the variables I declared should follow the convention of all lowercase The appropriate rule would be something like should match a z a z0 9 2 30 Notice the lowercase letters in the regular expres
91. to start Pylint can tell you where you may have run astray and point you in the direction to figure out what you have done and how to do better This tutorial is all about approaching coding standards with little or no knowledge of in depth programming or the code standards themselves It s the equivalent of skipping the manual and jumping right in My command line prompt for these examples is robertk01 Desktops 11 2 Getting Started Running Pylint with no arguments will invoke the help dialogue and give you a idea of the arguments available to you Do that now i e robertk01 Desktop pylint a bunch of stuff A couple of the options that we ll focus on here are 35 Pylint Documentation Release 1 5 0 Master generate rcfile file Commands help msg msg id Commands help msg msg id Message control disable msg ids Reports files output y or n yeports cey or nm output format format Also pay attention to the last bit of help output This gives you a hint of what Pylint is going to pick on Output Using the default text output the message format is MESSAGE TYPE LINE NUM OBJECT MESSAGE There are 5 kind of message types C convention for programming standard violation R refactor for bad code smell W warning for python specific problems E error fo
92. tring checker which crashed when it encountered a bytes string with a format method called Don t warn about no self use for builtin properties Fix a false positive for bad reversed sequence when a subclass of a dict provides a reversed method Change the default no docstring rgx so missing docstring isn t emitted for private functions Don t emit redefined outer name for future directives Closes issue 520 Provide some hints for the bad builtin message Closes issue 522 When checking for invalid arguments to a callable in typecheck py look up for the __init__ in case the found new comes from builtins Since the __new__ comes from builtins it will not have attached any information regarding what parameters it expects so the check will be useless Retrieving __init__ in that case will at least detect a couple of false negatives Closes issue 429 Don t emit no member for classes with unknown bases Since we don t know what those bases might add we simply ignore the error in this case Lookup in the implicit metaclass when checking for no member if the class in question has an implicit meta class which is True for new style classes Closes issue 438 Add two new warnings duplicate bases and inconsistent mro duplicate bases is emitted when a class has the same bases listed more than once in its bases definition while inconsistent mro is emitted when no sane mro hierarchy can be determined Closes issue 526
93. uently Asked Questions Pylint Documentation Release 1 5 0 12 6 3 6 3 Pylint keeps crashing with Maximum recursion depth exceeded Pylint can crash with this error if you have a string in your analyzed program created by joining a lot of strings with the addition operator Due to how Pylint works visiting nodes on a AST tree and due to how the BinOp node is represented the node which represents the string 1 1 for instance the same visit method will be called over and over again leading to a maximum recursion error You can alleviate this problem by passing the flag optimize ast y to Pylint This will activate an optimization which will transform such AST subtrees into the final resulting string This flag is off by default If this is not the case please report a bug 12 6 4 6 4 I think I found a bug in Pylint What should do Read http docs pylint org contribute bug reports feedback 12 6 5 6 5 I have a question about Pylint that isn t answered here Read http docs pylint org contribute mailing lists 12 6 6 Troubleshooting 45 Pylint Documentation Release 1 5 0 46 Chapter 12 Frequently Asked Questions CHAPTER 13 Some projects using Pylint The following projects are known to use Pylint to help develop better code OSAF Chandler http www osafoundation org Xen http www xensource com CPS http www nuxeo org ERPS http www erp5 org pyxmpp http pyxmpp jabbe
94. unpacking non sequence to instance attribute unpacking as well Fix explicit checking of python script 1 2 regression 219 Restore init hook renamed accidentally into init hooks in 1 2 0 211 Add indexing exception warning which detects that indexing an exception occurs in Python 2 behaviour removed in Python 3 2014 04 18 1 2 0 Pass the current python paths to pylint process when invoked via epylint Fixes BitBucket issue 133 Add i include ids and s symbols back as completely ignored options Fixes BitBucket issue 180 Extend the number of cases in which logging calls are detected Fixes bitbucket issue 182 Improve pragma handling to not detect pylint strings in non comments Fixes BitBucket issue 79 60 Chapter 15 Changes amp Contributors Pylint Documentation Release 1 5 0 Do not crash with UnknownMessage if an unknown message ID name appears in disable or enable in the configuration Patch by Cole Robinson Fixes bitbucket issue 170 Add new warning eval used checking that the builtin function eval was used Make it possible to show a naming hint for invalid name by setting include naming hint Also make the naming hints configurable Fixes BitBucket issue 138 Added support for enforcing multiple but consistent name styles for different name types inside a single module based on a patch written by morbo google com Also warn about empty docstrings on ov
95. upport for Python 2 5 Each message now comes with a confidence level attached and can be filtered base on this level This allows to filter out all messages that were emitted even though an inference failure happened during checking Improved presenting unused import message Closes issue 293 Add new checker for finding spelling errors New messages wrong spelling in comment wrong spelling in docstring New options spelling dict spelling ignore words e Add new j option for running checks in sub processes Added new checks for line endings if they are mixed LF vs CRLF or if they are not as expected New messages mixed line endings unexpected line ending format New option expected line ending format e dangerous default value no longer evaluates the value of the arguments which could result in long error mes sages or sensitive data being leaked Closes issue 282 Fix a false positive with string formatting checker when encountering a string which uses only position based arguments Closes issue 285 Fix a false positive with string formatting checker when using keyword argument packing Closes issue 288 Proper handle class level scope for lambdas Handle too few format args or too many format args for format strings with both named and positional fields Closes issue 286 Analyze only strings by the string format checker Closes issue 287 Properly handle nested format string fi
96. ut can be separately configured with the lt name type gt hint options 6 1 Naming Styles 21 Pylint Documentation Release 1 5 0 22 Chapter 6 Configuration CHAPTER 7 Extending Pylint 7 1 Writing your own checker You can find some simple examples in the examples directory of the distribution custom py and custom raw py I ll try to quickly explain the essentials here First there are two kinds of checkers raw checkers which are analysing each module as a raw file stream ast checkers which are working on an ast representation of the module The ast representation used is an extension of the one provided with the standard Python distribution in the ast package The extension adds additional information and methods on the tree nodes to ease navigation and code introspection An AST checker is a visitor and should implement visit lowered class name gt or leave lowered class name gt methods for the nodes it s interested in To get description of the different classes used in an ast tree look at the ast package documentation Checkers are ordered by priority For each module Pylint s engine 1 give the module source file as a stream to raw checkers 2 get an ast representation for the module 3 make a depth first descent of the tree calling visit lt gt on each AST checker when entering a node and leave on the back traversal Notice that the source code is probably the best source of
97. vc and parseable output formats as well as killing include ids and symbols options Do not emit fixme for every line if the config value notes is empty but fixme is enabled Emit warnings about lines exceeding the column limit when those lines are inside multiline docstrings Do not double check parameter names with the regex for parameters and inline variables Added a new warning missing final newline C0304 for files missing the final newline Methods that are decorated as properties are now treated as attributes for the purposes of name checking Names of derived instance class member are not checked any more Names in global statements are now checked against the regular expression for constants For toplevel name assignment the class name regex will be used if pylint can detect that value on the right hand side is a class like collections namedtuple Simplified invalid name message 62 Chapter 15 Changes amp Contributors Pylint Documentation Release 1 5 0 Added a new warning invalid encoded data VVOS 12 for files that contain data that cannot be decoded with the specified or default encoding New warning bad open mode W 1501 for calls to open or file that specify invalid open modes Original implementation by Sasha Issayev New warning old style class C1001 for classes that do not have any base class Add new name type class attribute for attributes defined in class scope By defaul
98. x bla x param y bla y type y int def init self x y pass class ClassFoo object Google style docstring foo Args X float bla x y ane gt bla y def init self x y pass In some cases having to document all parameters is a nuisance for instance if many of your functions or methods just follow a common interface To remove this burden the checker accepts missing parameter documentation if one of the following phrases is found in the docstring 16 Chapter 5 Optional Pylint checkers in the extensions module Pylint Documentation Release 1 5 0 For the other parameters see For the parameters see with arbitrary whitespace between the words Please add a link to the docstring defining the interface e g a superclass method after see def callback x y z Sphinx style doestring for callback spatam xt bla x type x int For the other parameters see class MyFrameworkUsingAndDefiningCallback EE 3 return x y z def callback x y z Google style docstring for callback AFGSZ x ipt r bla x For the other parameters see class MyFrameworkUsingAndDefiningCallback pre return x y z Naming inconsistencies in existing parameter and their type documentations are still detected By default omitting the parameter documentation of a function altogether is tolerated without any warnings If you want to switch off t
99. ylint If you can not find it in the tracker create a new issue there or discuss your problem on the code quality python org mailing list The code quality mailing list is also a nice place to provide feedback about Pylint since it is shared with other tools that aim at improving the quality of python code Note that if you don t find something you have expected in Pylint s issue tracker it may be because it is an issue with one of its dependencies namely astroid and logilab common https bitbucket org logilab astroid http www logilab org project logilab common 10 2 Mailing lists Use the code quality 9 python org mailing list for anything related to Pylint This is in most cases better than sending an email directly to the author since others will benefit from the exchange and you ll be more likely answered by someone subscribed to the list You can subscribe to this mailing list at http mail python org mailman listinfo code quality Archives are available at http mail python org pipermail code quality Archives before April 2013 are available at http lists logilab org pipermail python projects 10 3 Forge Pylint is developed using the mercurial distributed version control system You can clone Pylint and its dependencies from hg clone https bitbucket org logilab pylint hg clone https bitbucket org logilab astroid hg clone http hg logilab org logilab common 31 Pylint Documentation
100. ylint d subdirectory of the user s home directory if it is found not always findable on Windows plat forms e pylint d directory in the current directory 42 Chapter 12 Frequently Asked Questions Pylint Documentation Release 1 5 0 12 3 3 3 3 How do find the option name for pylintrc corresponding to a specific command line option You can always generate a sample pylintrc file with generate refile Every option present on the command line before this will be included in the rc file For example pylint disable bare except invalid name class rgx A Z a z generate rcfil 12 3 4 3 4 ld rather not run Pylint from the command line Can integrate it with my editor Much probably Read http docs pylint org ide integration 12 4 4 Message Control 12 4 1 4 1 Is it possible to locally disable a particular message Yes this feature has been added in Pylint 0 11 This may be done by adding pylint disable some message another one at the desired block level or at the end of the desired line of code 12 4 2 4 2 Is there a way to disable a message for a particular module only Yes you can disable or enable globally disabled messages at the module level by adding the corresponding option in a comment at the top of the file pylint disable wildcard import method hidden pylint enable too many lines 12 4 3 4 3 How can tell Pylint to never check a given module
101. ypecheck checker introducing the following checks E1101 access to unexistent member implements 10430 remove the need of E0201 and so some options has been moved from the classes checker to this one 15 1 ChangeLog for Pylint 71 Pylint Documentation Release 1 5 0 E1102 calling a non callable object E1111 and W1111 when an assignment is done on a function call but the inferred function returns None implements 10431 change in the base checker checks module level and instance attribute names new const rgx and attr rgx configuration option implements 10209 and 10440 list comprehension and generator expression variables have their own regular expression the inlinevar rgx option implements 9146 the C0101 check with its min name length option has been removed this can be specified in the regxp after all WO0103 and W0121 are now handled by the variables checker W0103 is now W0603 and W0604 has been splitted into different messages WO0131 and W0132 messages have been reclassified to C0111 and C0112 respectively new VV0104 message on statement without effect regexp support for dummy variables dummy variables rgx option replace dummy variables implements 10027 better global statement handling see W0602 W0603 W0604 messages implements 10344 and 10236 debug mode option disabling all checkers without error message and filtering others to only display error

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