pylint

Pylint global options and switches
----------------------------------

Pylint provides global options and switches.

General options
~~~~~~~~~~~~~~~
:rcfile:
  Specify a configuration file.
:init-hook:
  Python code to execute, usually for sys.path manipulation such as
  pygtk.require().
:errors-only:
  In error mode, checkers without error messages are disabled and for others,
  only the ERROR messages are displayed, and no reports are done by default.
:py3k:
  In Python 3 porting mode, all checkers will be disabled and only messages
  emitted by the porting checker will be displayed.
:verbose:
  In verbose mode, extra non-checker-related info will be displayed.
:ignore:
  Add files or directories to the blacklist. They should be base names, not
  paths.

  Default: ``CVS``
:ignore-patterns:
  Add files or directories matching the regex patterns to the blacklist. The
  regex matches against base names, not paths.
:persistent:
  Pickle collected data for later comparisons.

  Default: ``yes``
:load-plugins:
  List of plugins (as comma separated values of python modules names) to load,
  usually to register additional checkers.
:jobs:
  Use multiple processes to speed up Pylint. Specifying 0 will auto-detect the
  number of processors available to use.

  Default: ``1``
:unsafe-load-any-extension:
  Allow loading of arbitrary C extensions. Extensions are imported into the
  active Python interpreter and may run arbitrary code.
:limit-inference-results:
  Control the amount of potential inferred values when inferring a single
  object. This can help the performance when dealing with large functions or
  complex, nested conditions.

  Default: ``100``
:extension-pkg-whitelist:
  A comma-separated list of package or module names from where C extensions may
  be loaded. Extensions are loading into the active Python interpreter and may
  run arbitrary code.
:suggestion-mode:
  When enabled, pylint would attempt to guess common misconfiguration and emit
  user-friendly hints instead of false-positive error messages.

  Default: ``yes``
:exit-zero:
  Always return a 0 (non-error) status code, even if lint errors are found.
  This is primarily useful in continuous integration scripts.
:long-help:
  more verbose help.

Commands options
~~~~~~~~~~~~~~~~
:help-msg:
  Display a help message for the given message id and exit. The value may be a
  comma separated list of message ids.
:list-msgs:
  Generate pylint's messages.
:list-groups:
  List pylint's message groups.
:list-conf-levels:
  Generate pylint's confidence levels.
:full-documentation:
  Generate pylint's full documentation.
:generate-rcfile:
  Generate a sample configuration file according to the current configuration.
  You can put other options before this one to get them in the generated
  configuration.
:generate-man:
  Generate pylint's man page.

Messages control options
~~~~~~~~~~~~~~~~~~~~~~~~
:confidence:
  Only show warnings with the listed confidence levels. Leave empty to show
  all. Valid levels: HIGH, INFERENCE, INFERENCE_FAILURE, UNDEFINED.
:enable:
  Enable the message, report, category or checker with the given id(s). You can
  either give multiple identifier separated by comma (,) or put this option
  multiple time (only on the command line, not in the configuration file where
  it should appear only once). See also the "--disable" option for examples.

  Default: ``c-extension-no-member``
:disable:
  Disable the message, report, category or checker with the given id(s). You
  can either give multiple identifiers separated by comma (,) or put this
  option multiple times (only on the command line, not in the configuration
  file where it should appear only once). You can also use "--disable=all" to
  disable everything first and then reenable specific checks. For example, if
  you want to run only the similarities checker, you can use "--disable=all
  --enable=similarities". If you want to run only the classes checker, but have
  no Warning level messages displayed, use "--disable=all --enable=classes
  --disable=W".

  Default: ``print-statement,parameter-unpacking,unpacking-in-except,old-raise-syntax,backtick,long-suffix,old-ne-operator,old-octal-literal,import-star-module-level,non-ascii-bytes-literal,raw-checker-failed,bad-inline-option,locally-disabled,file-ignored,suppressed-message,useless-suppression,deprecated-pragma,use-symbolic-message-instead,apply-builtin,basestring-builtin,buffer-builtin,cmp-builtin,coerce-builtin,execfile-builtin,file-builtin,long-builtin,raw_input-builtin,reduce-builtin,standarderror-builtin,unicode-builtin,xrange-builtin,coerce-method,delslice-method,getslice-method,setslice-method,no-absolute-import,old-division,dict-iter-method,dict-view-method,next-method-called,metaclass-assignment,indexing-exception,raising-string,reload-builtin,oct-method,hex-method,nonzero-method,cmp-method,input-builtin,round-builtin,intern-builtin,unichr-builtin,map-builtin-not-iterating,zip-builtin-not-iterating,range-builtin-not-iterating,filter-builtin-not-iterating,using-cmp-argument,eq-without-hash,div-method,idiv-method,rdiv-method,exception-message-attribute,invalid-str-codec,sys-max-int,bad-python3-import,deprecated-string-function,deprecated-str-translate-call,deprecated-itertools-function,deprecated-types-field,next-method-defined,dict-items-not-iterating,dict-keys-not-iterating,dict-values-not-iterating,deprecated-operator-function,deprecated-urllib-function,xreadlines-attribute,deprecated-sys-function,exception-escape,comprehension-escape``

Reports options
~~~~~~~~~~~~~~~
:output-format:
  Set the output format. Available formats are text, parseable, colorized, json
  and msvs (visual studio). You can also give a reporter class, e.g.
  mypackage.mymodule.MyReporterClass.

  Default: ``text``
:reports:
  Tells whether to display a full report or only the messages.
:evaluation:
  Python expression which should return a note less than 10 (10 is the highest
  note). You have access to the variables errors warning, statement which
  respectively contain the number of errors / warnings messages and the total
  number of statements analyzed. This is used by the global evaluation report
  (RP0004).

  Default: ``10.0 - ((float(5 * error + warning + refactor + convention) / statement) * 10)``
:score:
  Activate the evaluation score.

  Default: ``yes``
:msg-template:
  Template used to display messages. This is a python new-style format string
  used to format the message information. See doc for all details.

Pylint checkers' options and switches
-------------------------------------

Pylint checkers can provide three set of features:

* options that control their execution,
* messages that they can raise,
* reports that they can generate.

Below is a list of all checkers and their features.

Async checker
~~~~~~~~~~~~~

Verbatim name of the checker is ``async``.

Async checker Messages
^^^^^^^^^^^^^^^^^^^^^^
:not-async-context-manager (E1701): *Async context manager '%s' doesn't implement __aenter__ and __aexit__.*
  Used when an async context manager is used with an object that does not
  implement the async context management protocol. This message can't be emitted
  when using Python < 3.5.
:yield-inside-async-function (E1700): *Yield inside async function*
  Used when an `yield` or `yield from` statement is found inside an async
  function. This message can't be emitted when using Python < 3.5.


Basic checker
~~~~~~~~~~~~~

Verbatim name of the checker is ``basic``.

Basic checker Options
^^^^^^^^^^^^^^^^^^^^^
:good-names:
  Good variable names which should always be accepted, separated by a comma.

  Default: ``i,j,k,ex,Run,_``
:bad-names:
  Bad variable names which should always be refused, separated by a comma.

  Default: ``foo,bar,baz,toto,tutu,tata``
:name-group:
  Colon-delimited sets of names that determine each other's naming style when
  the name regexes allow several styles.
:include-naming-hint:
  Include a hint for the correct naming format with invalid-name.
:property-classes:
  List of decorators that produce properties, such as abc.abstractproperty. Add
  to this list to register other decorators that produce valid properties.
  These decorators are taken in consideration only for invalid-name.

  Default: ``abc.abstractproperty``
:argument-naming-style:
  Naming style matching correct argument names.

  Default: ``snake_case``
:argument-rgx:
  Regular expression matching correct argument names. Overrides argument-
  naming-style.
:attr-naming-style:
  Naming style matching correct attribute names.

  Default: ``snake_case``
:attr-rgx:
  Regular expression matching correct attribute names. Overrides attr-naming-
  style.
:class-naming-style:
  Naming style matching correct class names.

  Default: ``PascalCase``
:class-rgx:
  Regular expression matching correct class names. Overrides class-naming-
  style.
:class-attribute-naming-style:
  Naming style matching correct class attribute names.

  Default: ``any``
:class-attribute-rgx:
  Regular expression matching correct class attribute names. Overrides class-
  attribute-naming-style.
:const-naming-style:
  Naming style matching correct constant names.

  Default: ``UPPER_CASE``
:const-rgx:
  Regular expression matching correct constant names. Overrides const-naming-
  style.
:function-naming-style:
  Naming style matching correct function names.

  Default: ``snake_case``
:function-rgx:
  Regular expression matching correct function names. Overrides function-
  naming-style.
:inlinevar-naming-style:
  Naming style matching correct inline iteration names.

  Default: ``any``
:inlinevar-rgx:
  Regular expression matching correct inline iteration names. Overrides
  inlinevar-naming-style.
:method-naming-style:
  Naming style matching correct method names.

  Default: ``snake_case``
:method-rgx:
  Regular expression matching correct method names. Overrides method-naming-
  style.
:module-naming-style:
  Naming style matching correct module names.

  Default: ``snake_case``
:module-rgx:
  Regular expression matching correct module names. Overrides module-naming-
  style.
:variable-naming-style:
  Naming style matching correct variable names.

  Default: ``snake_case``
:variable-rgx:
  Regular expression matching correct variable names. Overrides variable-
  naming-style.
:no-docstring-rgx:
  Regular expression which should only match function or class names that do
  not require a docstring.

  Default: ``^_``
:docstring-min-length:
  Minimum line length for functions/classes that require docstrings, shorter
  ones are exempt.

  Default: ``-1``

Basic checker Messages
^^^^^^^^^^^^^^^^^^^^^^
:not-in-loop (E0103): *%r not properly in loop*
  Used when break or continue keywords are used outside a loop.
:function-redefined (E0102): *%s already defined line %s*
  Used when a function / class / method is redefined.
:continue-in-finally (E0116): *'continue' not supported inside 'finally' clause*
  Emitted when the `continue` keyword is found inside a finally clause, which is
  a SyntaxError.
:abstract-class-instantiated (E0110): *Abstract class %r with abstract methods instantiated*
  Used when an abstract class with `abc.ABCMeta` as metaclass has abstract
  methods and is instantiated.
:star-needs-assignment-target (E0114): *Can use starred expression only in assignment target*
  Emitted when a star expression is not used in an assignment target.
:duplicate-argument-name (E0108): *Duplicate argument name %s in function definition*
  Duplicate argument names in function definitions are syntax errors.
:return-in-init (E0101): *Explicit return in __init__*
  Used when the special class method __init__ has an explicit return value.
:too-many-star-expressions (E0112): *More than one starred expression in assignment*
  Emitted when there are more than one starred expressions (`*x`) in an
  assignment. This is a SyntaxError.
:nonlocal-and-global (E0115): *Name %r is nonlocal and global*
  Emitted when a name is both nonlocal and global.
:used-prior-global-declaration (E0118): *Name %r is used prior to global declaration*
  Emitted when a name is used prior a global declaration, which results in an
  error since Python 3.6. This message can't be emitted when using Python < 3.6.
:return-outside-function (E0104): *Return outside function*
  Used when a "return" statement is found outside a function or method.
:return-arg-in-generator (E0106): *Return with argument inside generator*
  Used when a "return" statement with an argument is found outside in a
  generator function or method (e.g. with some "yield" statements). This message
  can't be emitted when using Python >= 3.3.
:invalid-star-assignment-target (E0113): *Starred assignment target must be in a list or tuple*
  Emitted when a star expression is used as a starred assignment target.
:bad-reversed-sequence (E0111): *The first reversed() argument is not a sequence*
  Used when the first argument to reversed() builtin isn't a sequence (does not
  implement __reversed__, nor __getitem__ and __len__
:nonexistent-operator (E0107): *Use of the non-existent %s operator*
  Used when you attempt to use the C-style pre-increment or pre-decrement
  operator -- and ++, which doesn't exist in Python.
:yield-outside-function (E0105): *Yield outside function*
  Used when a "yield" statement is found outside a function or method.
:init-is-generator (E0100): *__init__ method is a generator*
  Used when the special class method __init__ is turned into a generator by a
  yield in its body.
:misplaced-format-function (E0119): *format function is not called on str*
  Emitted when format function is not called on str object. e.g doing
  print("value: {}").format(123) instead of print("value: {}".format(123)). This
  might not be what the user intended to do.
:nonlocal-without-binding (E0117): *nonlocal name %s found without binding*
  Emitted when a nonlocal variable does not have an attached name somewhere in
  the parent scopes
:lost-exception (W0150): *%s statement in finally block may swallow exception*
  Used when a break or a return statement is found inside the finally clause of
  a try...finally block: the exceptions raised in the try clause will be
  silently swallowed instead of being re-raised.
:assert-on-tuple (W0199): *Assert called on a 2-uple. Did you mean 'assert x,y'?*
  A call of assert on a tuple will always evaluate to true if the tuple is not
  empty, and will always evaluate to false if it is.
:comparison-with-callable (W0143): *Comparing against a callable, did you omit the parenthesis?*
  This message is emitted when pylint detects that a comparison with a callable
  was made, which might suggest that some parenthesis were omitted, resulting in
  potential unwanted behaviour.
:dangerous-default-value (W0102): *Dangerous default value %s as argument*
  Used when a mutable value as list or dictionary is detected in a default value
  for an argument.
:duplicate-key (W0109): *Duplicate key %r in dictionary*
  Used when a dictionary expression binds the same key multiple times.
:useless-else-on-loop (W0120): *Else clause on loop without a break statement*
  Loops should only have an else clause if they can exit early with a break
  statement, otherwise the statements under else should be on the same scope as
  the loop itself.
:expression-not-assigned (W0106): *Expression "%s" is assigned to nothing*
  Used when an expression that is not a function call is assigned to nothing.
  Probably something else was intended.
:confusing-with-statement (W0124): *Following "as" with another context manager looks like a tuple.*
  Emitted when a `with` statement component returns multiple values and uses
  name binding with `as` only for a part of those values, as in with ctx() as a,
  b. This can be misleading, since it's not clear if the context manager returns
  a tuple or if the node without a name binding is another context manager.
:unnecessary-lambda (W0108): *Lambda may not be necessary*
  Used when the body of a lambda expression is a function call on the same
  argument list as the lambda itself; such lambda expressions are in all but a
  few cases replaceable with the function being called in the body of the
  lambda.
:assign-to-new-keyword (W0111): *Name %s will become a keyword in Python %s*
  Used when assignment will become invalid in future Python release due to
  introducing new keyword.
:pointless-statement (W0104): *Statement seems to have no effect*
  Used when a statement doesn't have (or at least seems to) any effect.
:pointless-string-statement (W0105): *String statement has no effect*
  Used when a string is used as a statement (which of course has no effect).
  This is a particular case of W0104 with its own message so you can easily
  disable it if you're using those strings as documentation, instead of
  comments.
:unnecessary-pass (W0107): *Unnecessary pass statement*
  Used when a "pass" statement that can be avoided is encountered.
:unreachable (W0101): *Unreachable code*
  Used when there is some code behind a "return" or "raise" statement, which
  will never be accessed.
:eval-used (W0123): *Use of eval*
  Used when you use the "eval" function, to discourage its usage. Consider using
  `ast.literal_eval` for safely evaluating strings containing Python expressions
  from untrusted sources.
:exec-used (W0122): *Use of exec*
  Used when you use the "exec" statement (function for Python 3), to discourage
  its usage. That doesn't mean you cannot use it !
:using-constant-test (W0125): *Using a conditional statement with a constant value*
  Emitted when a conditional statement (If or ternary if) uses a constant value
  for its test. This might not be what the user intended to do.
:literal-comparison (R0123): *Comparison to literal*
  Used when comparing an object to a literal, which is usually what you do not
  want to do, since you can compare to a different literal than what was
  expected altogether.
:comparison-with-itself (R0124): *Redundant comparison - %s*
  Used when something is compared against itself.
:invalid-name (C0103): *%s name "%s" doesn't conform to %s*
  Used when the name doesn't conform to naming rules associated to its type
  (constant, variable, class...).
:blacklisted-name (C0102): *Black listed name "%s"*
  Used when the name is listed in the black list (unauthorized names).
:misplaced-comparison-constant (C0122): *Comparison should be %s*
  Used when the constant is placed on the left side of a comparison. It is
  usually clearer in intent to place it in the right hand side of the
  comparison.
:singleton-comparison (C0121): *Comparison to %s should be %s*
  Used when an expression is compared to singleton values like True, False or
  None.
:empty-docstring (C0112): *Empty %s docstring*
  Used when a module, function, class or method has an empty docstring (it would
  be too easy ;).
:missing-docstring (C0111): *Missing %s docstring*
  Used when a module, function, class or method has no docstring.Some special
  methods like __init__ doesn't necessary require a docstring.
:unidiomatic-typecheck (C0123): *Using type() instead of isinstance() for a typecheck.*
  The idiomatic way to perform an explicit typecheck in Python is to use
  isinstance(x, Y) rather than type(x) == Y, type(x) is Y. Though there are
  unusual situations where these give different results.

Basic checker Reports
^^^^^^^^^^^^^^^^^^^^^
:RP0101: Statistics by type


Classes checker
~~~~~~~~~~~~~~~

Verbatim name of the checker is ``classes``.

Classes checker Options
^^^^^^^^^^^^^^^^^^^^^^^
:defining-attr-methods:
  List of method names used to declare (i.e. assign) instance attributes.

  Default: ``__init__,__new__,setUp``
:valid-classmethod-first-arg:
  List of valid names for the first argument in a class method.

  Default: ``cls``
:valid-metaclass-classmethod-first-arg:
  List of valid names for the first argument in a metaclass class method.

  Default: ``cls``
:exclude-protected:
  List of member names, which should be excluded from the protected access
  warning.

  Default: ``_asdict,_fields,_replace,_source,_make``

Classes checker Messages
^^^^^^^^^^^^^^^^^^^^^^^^
:access-member-before-definition (E0203): *Access to member %r before its definition line %s*
  Used when an instance member is accessed before it's actually assigned.
:method-hidden (E0202): *An attribute defined in %s line %s hides this method*
  Used when a class defines a method which is hidden by an instance attribute
  from an ancestor class or set by some client code.
:assigning-non-slot (E0237): *Assigning to attribute %r not defined in class slots*
  Used when assigning to an attribute not defined in the class slots.
:duplicate-bases (E0241): *Duplicate bases for class %r*
  Used when a class has duplicate bases.
:inconsistent-mro (E0240): *Inconsistent method resolution order for class %r*
  Used when a class has an inconsistent method resolution order.
:inherit-non-class (E0239): *Inheriting %r, which is not a class.*
  Used when a class inherits from something which is not a class.
:invalid-slots (E0238): *Invalid __slots__ object*
  Used when an invalid __slots__ is found in class. Only a string, an iterable
  or a sequence is permitted.
:invalid-slots-object (E0236): *Invalid object %r in __slots__, must contain only non empty strings*
  Used when an invalid (non-string) object occurs in __slots__.
:no-method-argument (E0211): *Method has no argument*
  Used when a method which should have the bound instance as first argument has
  no argument defined.
:no-self-argument (E0213): *Method should have "self" as first argument*
  Used when a method has an attribute different the "self" as first argument.
  This is considered as an error since this is a so common convention that you
  shouldn't break it!
:unexpected-special-method-signature (E0302): *The special method %r expects %s param(s), %d %s given*
  Emitted when a special method was defined with an invalid number of
  parameters. If it has too few or too many, it might not work at all.
:non-iterator-returned (E0301): *__iter__ returns non-iterator*
  Used when an __iter__ method returns something which is not an iterable (i.e.
  has no `__next__` method)
:invalid-length-returned (E0303): *__len__ does not return non-negative integer*
  Used when a __len__ method returns something which is not a non-negative
  integer
:protected-access (W0212): *Access to a protected member %s of a client class*
  Used when a protected member (i.e. class member with a name beginning with an
  underscore) is access outside the class or a descendant of the class where
  it's defined.
:attribute-defined-outside-init (W0201): *Attribute %r defined outside __init__*
  Used when an instance attribute is defined outside the __init__ method.
:no-init (W0232): *Class has no __init__ method*
  Used when a class has no __init__ method, neither its parent classes.
:abstract-method (W0223): *Method %r is abstract in class %r but is not overridden*
  Used when an abstract method (i.e. raise NotImplementedError) is not
  overridden in concrete class.
:arguments-differ (W0221): *Parameters differ from %s %r method*
  Used when a method has a different number of arguments than in the implemented
  interface or in an overridden method.
:signature-differs (W0222): *Signature differs from %s %r method*
  Used when a method signature is different than in the implemented interface or
  in an overridden method.
:bad-staticmethod-argument (W0211): *Static method with %r as first argument*
  Used when a static method has "self" or a value specified in valid-
  classmethod-first-arg option or valid-metaclass-classmethod-first-arg option
  as first argument.
:useless-super-delegation (W0235): *Useless super delegation in method %r*
  Used whenever we can detect that an overridden method is useless, relying on
  super() delegation to do the same thing as another method from the MRO.
:non-parent-init-called (W0233): *__init__ method from a non direct base class %r is called*
  Used when an __init__ method is called on a class which is not in the direct
  ancestors for the analysed class.
:super-init-not-called (W0231): *__init__ method from base class %r is not called*
  Used when an ancestor class method has an __init__ method which is not called
  by a derived class.
:useless-object-inheritance (R0205): *Class %r inherits from object, can be safely removed from bases in python3*
  Used when a class inherit from object, which under python3 is implicit, hence
  can be safely removed from bases.
:no-classmethod-decorator (R0202): *Consider using a decorator instead of calling classmethod*
  Used when a class method is defined without using the decorator syntax.
:no-staticmethod-decorator (R0203): *Consider using a decorator instead of calling staticmethod*
  Used when a static method is defined without using the decorator syntax.
:no-self-use (R0201): *Method could be a function*
  Used when a method doesn't use its bound instance, and so could be written as
  a function.
:single-string-used-for-slots (C0205): *Class __slots__ should be a non-string iterable*
  Used when a class __slots__ is a simple string, rather than an iterable.
:bad-classmethod-argument (C0202): *Class method %s should have %s as first argument*
  Used when a class method has a first argument named differently than the value
  specified in valid-classmethod-first-arg option (default to "cls"),
  recommended to easily differentiate them from regular instance methods.
:bad-mcs-classmethod-argument (C0204): *Metaclass class method %s should have %s as first argument*
  Used when a metaclass class method has a first argument named differently than
  the value specified in valid-metaclass-classmethod-first-arg option (default
  to "mcs"), recommended to easily differentiate them from regular instance
  methods.
:bad-mcs-method-argument (C0203): *Metaclass method %s should have %s as first argument*
  Used when a metaclass method has a first argument named differently than the
  value specified in valid-classmethod-first-arg option (default to "cls"),
  recommended to easily differentiate them from regular instance methods.
:method-check-failed (F0202): *Unable to check methods signature (%s / %s)*
  Used when Pylint has been unable to check methods signature compatibility for
  an unexpected reason. Please report this kind if you don't make sense of it.


Design checker
~~~~~~~~~~~~~~

Verbatim name of the checker is ``design``.

Design checker Options
^^^^^^^^^^^^^^^^^^^^^^
:max-args:
  Maximum number of arguments for function / method.

  Default: ``5``
:max-locals:
  Maximum number of locals for function / method body.

  Default: ``15``
:max-returns:
  Maximum number of return / yield for function / method body.

  Default: ``6``
:max-branches:
  Maximum number of branch for function / method body.

  Default: ``12``
:max-statements:
  Maximum number of statements in function / method body.

  Default: ``50``
:max-parents:
  Maximum number of parents for a class (see R0901).

  Default: ``7``
:max-attributes:
  Maximum number of attributes for a class (see R0902).

  Default: ``7``
:min-public-methods:
  Minimum number of public methods for a class (see R0903).

  Default: ``2``
:max-public-methods:
  Maximum number of public methods for a class (see R0904).

  Default: ``20``
:max-bool-expr:
  Maximum number of boolean expressions in an if statement.

  Default: ``5``

Design checker Messages
^^^^^^^^^^^^^^^^^^^^^^^
:too-few-public-methods (R0903): *Too few public methods (%s/%s)*
  Used when class has too few public methods, so be sure it's really worth it.
:too-many-ancestors (R0901): *Too many ancestors (%s/%s)*
  Used when class has too many parent classes, try to reduce this to get a
  simpler (and so easier to use) class.
:too-many-arguments (R0913): *Too many arguments (%s/%s)*
  Used when a function or method takes too many arguments.
:too-many-boolean-expressions (R0916): *Too many boolean expressions in if statement (%s/%s)*
  Used when an if statement contains too many boolean expressions.
:too-many-branches (R0912): *Too many branches (%s/%s)*
  Used when a function or method has too many branches, making it hard to
  follow.
:too-many-instance-attributes (R0902): *Too many instance attributes (%s/%s)*
  Used when class has too many instance attributes, try to reduce this to get a
  simpler (and so easier to use) class.
:too-many-locals (R0914): *Too many local variables (%s/%s)*
  Used when a function or method has too many local variables.
:too-many-public-methods (R0904): *Too many public methods (%s/%s)*
  Used when class has too many public methods, try to reduce this to get a
  simpler (and so easier to use) class.
:too-many-return-statements (R0911): *Too many return statements (%s/%s)*
  Used when a function or method has too many return statement, making it hard
  to follow.
:too-many-statements (R0915): *Too many statements (%s/%s)*
  Used when a function or method has too many statements. You should then split
  it in smaller functions / methods.


Exceptions checker
~~~~~~~~~~~~~~~~~~

Verbatim name of the checker is ``exceptions``.

Exceptions checker Options
^^^^^^^^^^^^^^^^^^^^^^^^^^
:overgeneral-exceptions:
  Exceptions that will emit a warning when being caught. Defaults to
  "BaseException, Exception".

  Default: ``BaseException,Exception``

Exceptions checker Messages
^^^^^^^^^^^^^^^^^^^^^^^^^^^
:bad-except-order (E0701): *Bad except clauses order (%s)*
  Used when except clauses are not in the correct order (from the more specific
  to the more generic). If you don't fix the order, some exceptions may not be
  caught by the most specific handler.
:catching-non-exception (E0712): *Catching an exception which doesn't inherit from Exception: %s*
  Used when a class which doesn't inherit from Exception is used as an exception
  in an except clause.
:bad-exception-context (E0703): *Exception context set to something which is not an exception, nor None*
  Used when using the syntax "raise ... from ...", where the exception context
  is not an exception, nor None.
:notimplemented-raised (E0711): *NotImplemented raised - should raise NotImplementedError*
  Used when NotImplemented is raised instead of NotImplementedError
:raising-bad-type (E0702): *Raising %s while only classes or instances are allowed*
  Used when something which is neither a class, an instance or a string is
  raised (i.e. a `TypeError` will be raised).
:raising-non-exception (E0710): *Raising a new style class which doesn't inherit from BaseException*
  Used when a new style class which doesn't inherit from BaseException is
  raised.
:misplaced-bare-raise (E0704): *The raise statement is not inside an except clause*
  Used when a bare raise is not used inside an except clause. This generates an
  error, since there are no active exceptions to be reraised. An exception to
  this rule is represented by a bare raise inside a finally clause, which might
  work, as long as an exception is raised inside the try block, but it is
  nevertheless a code smell that must not be relied upon.
:duplicate-except (W0705): *Catching previously caught exception type %s*
  Used when an except catches a type that was already caught by a previous
  handler.
:broad-except (W0703): *Catching too general exception %s*
  Used when an except catches a too general exception, possibly burying
  unrelated errors.
:raising-format-tuple (W0715): *Exception arguments suggest string formatting might be intended*
  Used when passing multiple arguments to an exception constructor, the first of
  them a string literal containing what appears to be placeholders intended for
  formatting
:binary-op-exception (W0711): *Exception to catch is the result of a binary "%s" operation*
  Used when the exception to catch is of the form "except A or B:". If intending
  to catch multiple, rewrite as "except (A, B):"
:wrong-exception-operation (W0716): *Invalid exception operation. %s*
  Used when an operation is done against an exception, but the operation is not
  valid for the exception in question. Usually emitted when having binary
  operations between exceptions in except handlers.
:bare-except (W0702): *No exception type(s) specified*
  Used when an except clause doesn't specify exceptions type to catch.
:try-except-raise (W0706): *The except handler raises immediately*
  Used when an except handler uses raise as its first or only operator. This is
  useless because it raises back the exception immediately. Remove the raise
  operator or the entire try-except-raise block!


Format checker
~~~~~~~~~~~~~~

Verbatim name of the checker is ``format``.

Format checker Options
^^^^^^^^^^^^^^^^^^^^^^
:max-line-length:
  Maximum number of characters on a single line.

  Default: ``100``
:ignore-long-lines:
  Regexp for a line that is allowed to be longer than the limit.

  Default: ``^\s*(# )?<?https?://\S+>?$``
:single-line-if-stmt:
  Allow the body of an if to be on the same line as the test if there is no
  else.
:single-line-class-stmt:
  Allow the body of a class to be on the same line as the declaration if body
  contains single statement.
:no-space-check:
  List of optional constructs for which whitespace checking is disabled. `dict-
  separator` is used to allow tabulation in dicts, etc.: {1  : 1,\n222: 2}.
  `trailing-comma` allows a space between comma and closing bracket: (a, ).
  `empty-line` allows space-only lines.

  Default: ``trailing-comma,dict-separator``
:max-module-lines:
  Maximum number of lines in a module.

  Default: ``1000``
:indent-string:
  String used as indentation unit. This is usually "    " (4 spaces) or "\t" (1
  tab).

  Default: ``'    '``
:indent-after-paren:
  Number of spaces of indent required inside a hanging or continued line.

  Default: ``4``
:expected-line-ending-format:
  Expected format of line ending, e.g. empty (any line ending), LF or CRLF.

Format checker Messages
^^^^^^^^^^^^^^^^^^^^^^^
:bad-indentation (W0311): *Bad indentation. Found %s %s, expected %s*
  Used when an unexpected number of indentation's tabulations or spaces has been
  found.
:mixed-indentation (W0312): *Found indentation with %ss instead of %ss*
  Used when there are some mixed tabs and spaces in a module.
:unnecessary-semicolon (W0301): *Unnecessary semicolon*
  Used when a statement is ended by a semi-colon (";"), which isn't necessary
  (that's python, not C ;).
:bad-whitespace (C0326): *%s space %s %s %s*
  Used when a wrong number of spaces is used around an operator, bracket or
  block opener.
:missing-final-newline (C0304): *Final newline missing*
  Used when the last line in a file is missing a newline.
:line-too-long (C0301): *Line too long (%s/%s)*
  Used when a line is longer than a given number of characters.
:mixed-line-endings (C0327): *Mixed line endings LF and CRLF*
  Used when there are mixed (LF and CRLF) newline signs in a file.
:multiple-statements (C0321): *More than one statement on a single line*
  Used when more than on statement are found on the same line.
:too-many-lines (C0302): *Too many lines in module (%s/%s)*
  Used when a module has too many lines, reducing its readability.
:trailing-newlines (C0305): *Trailing newlines*
  Used when there are trailing blank lines in a file.
:trailing-whitespace (C0303): *Trailing whitespace*
  Used when there is whitespace between the end of a line and the newline.
:unexpected-line-ending-format (C0328): *Unexpected line ending format. There is '%s' while it should be '%s'.*
  Used when there is different newline than expected.
:superfluous-parens (C0325): *Unnecessary parens after %r keyword*
  Used when a single item in parentheses follows an if, for, or other keyword.
:bad-continuation (C0330): *Wrong %s indentation%s%s.*
  TODO


Imports checker
~~~~~~~~~~~~~~~

Verbatim name of the checker is ``imports``.

Imports checker Options
^^^^^^^^^^^^^^^^^^^^^^^
:deprecated-modules:
  Deprecated modules which should not be used, separated by a comma.

  Default: ``optparse,tkinter.tix``
:import-graph:
  Create a graph of every (i.e. internal and external) dependencies in the
  given file (report RP0402 must not be disabled).
:ext-import-graph:
  Create a graph of external dependencies in the given file (report RP0402 must
  not be disabled).
:int-import-graph:
  Create a graph of internal dependencies in the given file (report RP0402 must
  not be disabled).
:known-standard-library:
  Force import order to recognize a module as part of the standard
  compatibility libraries.
:known-third-party:
  Force import order to recognize a module as part of a third party library.

  Default: ``enchant``
:analyse-fallback-blocks:
  Analyse import fallback blocks. This can be used to support both Python 2 and
  3 compatible code, which means that the block might have code that exists
  only in one or another interpreter, leading to false positives when analysed.
:allow-wildcard-with-all:
  Allow wildcard imports from modules that define __all__.

Imports checker Messages
^^^^^^^^^^^^^^^^^^^^^^^^
:relative-beyond-top-level (E0402): *Attempted relative import beyond top-level package*
  Used when a relative import tries to access too many levels in the current
  package.
:import-error (E0401): *Unable to import %s*
  Used when pylint has been unable to import a module.
:import-self (W0406): *Module import itself*
  Used when a module is importing itself.
:reimported (W0404): *Reimport %r (imported line %s)*
  Used when a module is reimported multiple times.
:relative-import (W0403): *Relative import %r, should be %r*
  Used when an import relative to the package directory is detected. This
  message can't be emitted when using Python >= 3.0.
:deprecated-module (W0402): *Uses of a deprecated module %r*
  Used a module marked as deprecated is imported.
:wildcard-import (W0401): *Wildcard import %s*
  Used when `from module import *` is detected.
:misplaced-future (W0410): *__future__ import is not the first non docstring statement*
  Python 2.5 and greater require __future__ import to be the first non docstring
  statement in the module.
:cyclic-import (R0401): *Cyclic import (%s)*
  Used when a cyclic import between two or more modules is detected.
:wrong-import-order (C0411): *%s should be placed before %s*
  Used when PEP8 import order is not respected (standard imports first, then
  third-party libraries, then local imports)
:wrong-import-position (C0413): *Import "%s" should be placed at the top of the module*
  Used when code and imports are mixed
:useless-import-alias (C0414): *Import alias does not rename original package*
  Used when an import alias is same as original package.e.g using import numpy
  as numpy instead of import numpy as np
:ungrouped-imports (C0412): *Imports from package %s are not grouped*
  Used when imports are not grouped by packages
:multiple-imports (C0410): *Multiple imports on one line (%s)*
  Used when import statement importing multiple modules is detected.

Imports checker Reports
^^^^^^^^^^^^^^^^^^^^^^^
:RP0401: External dependencies
:RP0402: Modules dependencies graph


Logging checker
~~~~~~~~~~~~~~~

Verbatim name of the checker is ``logging``.

Logging checker Options
^^^^^^^^^^^^^^^^^^^^^^^
:logging-modules:
  Logging modules to check that the string format arguments are in logging
  function parameter format.

  Default: ``logging``
:logging-format-style:
  Format style used to check logging format string. `old` means using %
  formatting, while `new` is for `{}` formatting.

  Default: ``old``

Logging checker Messages
^^^^^^^^^^^^^^^^^^^^^^^^
:logging-format-truncated (E1201): *Logging format string ends in middle of conversion specifier*
  Used when a logging statement format string terminates before the end of a
  conversion specifier.
:logging-too-few-args (E1206): *Not enough arguments for logging format string*
  Used when a logging format string is given too few arguments.
:logging-too-many-args (E1205): *Too many arguments for logging format string*
  Used when a logging format string is given too many arguments.
:logging-unsupported-format (E1200): *Unsupported logging format character %r (%#02x) at index %d*
  Used when an unsupported format character is used in a logging statement
  format string.
:logging-not-lazy (W1201): *Specify string format arguments as logging function parameters*
  Used when a logging statement has a call form of "logging.<logging
  method>(format_string % (format_args...))". Such calls should leave string
  interpolation to the logging method itself and be written "logging.<logging
  method>(format_string, format_args...)" so that the program may avoid
  incurring the cost of the interpolation in those cases in which no message
  will be logged. For more, see http://www.python.org/dev/peps/pep-0282/.
:logging-format-interpolation (W1202): *Use % formatting in logging functions and pass the % parameters as arguments*
  Used when a logging statement has a call form of "logging.<logging
  method>(format_string.format(format_args...))". Such calls should use %
  formatting instead, but leave interpolation to the logging function by passing
  the parameters as arguments.
:logging-fstring-interpolation (W1203): *Use % formatting in logging functions and pass the % parameters as arguments*
  Used when a logging statement has a call form of "logging.method(f"..."))".
  Such calls should use % formatting instead, but leave interpolation to the
  logging function by passing the parameters as arguments.


Metrics checker
~~~~~~~~~~~~~~~

Verbatim name of the checker is ``metrics``.

Metrics checker Reports
^^^^^^^^^^^^^^^^^^^^^^^
:RP0701: Raw metrics


Miscellaneous checker
~~~~~~~~~~~~~~~~~~~~~

Verbatim name of the checker is ``miscellaneous``.

Miscellaneous checker Options
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
:notes:
  List of note tags to take in consideration, separated by a comma.

  Default: ``FIXME,XXX,TODO``

Miscellaneous checker Messages
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
:fixme (W0511):
  Used when a warning note as FIXME or XXX is detected.
:invalid-encoded-data (W0512): *Cannot decode using encoding "%s", unexpected byte at position %d*
  Used when a source line cannot be decoded using the specified source file
  encoding. This message can't be emitted when using Python >= 3.0.
:use-symbolic-message-instead (I0023):
  Used when a message is enabled or disabled by id.


Newstyle checker
~~~~~~~~~~~~~~~~

Verbatim name of the checker is ``newstyle``.

Newstyle checker Messages
^^^^^^^^^^^^^^^^^^^^^^^^^
:bad-super-call (E1003): *Bad first argument %r given to super()*
  Used when another argument than the current class is given as first argument
  of the super builtin.
:missing-super-argument (E1004): *Missing argument to super()*
  Used when the super builtin didn't receive an argument. This message can't be
  emitted when using Python >= 3.0.


Python3 checker
~~~~~~~~~~~~~~~

Verbatim name of the checker is ``python3``.

Python3 checker Messages
^^^^^^^^^^^^^^^^^^^^^^^^
:unpacking-in-except (E1603): *Implicit unpacking of exceptions is not supported in Python 3*
  Python3 will not allow implicit unpacking of exceptions in except clauses. See
  http://www.python.org/dev/peps/pep-3110/
:import-star-module-level (E1609): *Import * only allowed at module level*
  Used when the import star syntax is used somewhere else than the module level.
  This message can't be emitted when using Python >= 3.0.
:non-ascii-bytes-literal (E1610): *Non-ascii bytes literals not supported in 3.x*
  Used when non-ascii bytes literals are found in a program. They are no longer
  supported in Python 3. This message can't be emitted when using Python >= 3.0.
:parameter-unpacking (E1602): *Parameter unpacking specified*
  Used when parameter unpacking is specified for a function(Python 3 doesn't
  allow it)
:long-suffix (E1606): *Use of long suffix*
  Used when "l" or "L" is used to mark a long integer. This will not work in
  Python 3, since `int` and `long` types have merged. This message can't be
  emitted when using Python >= 3.0.
:old-octal-literal (E1608): *Use of old octal literal*
  Used when encountering the old octal syntax, removed in Python 3. To use the
  new syntax, prepend 0o on the number. This message can't be emitted when using
  Python >= 3.0.
:old-ne-operator (E1607): *Use of the <> operator*
  Used when the deprecated "<>" operator is used instead of "!=". This is
  removed in Python 3. This message can't be emitted when using Python >= 3.0.
:backtick (E1605): *Use of the `` operator*
  Used when the deprecated "``" (backtick) operator is used instead of the str()
  function.
:old-raise-syntax (E1604): *Use raise ErrorClass(args) instead of raise ErrorClass, args.*
  Used when the alternate raise syntax 'raise foo, bar' is used instead of
  'raise foo(bar)'.
:print-statement (E1601): *print statement used*
  Used when a print statement is used (`print` is a function in Python 3)
:deprecated-types-field (W1652): *Accessing a deprecated fields on the types module*
  Used when accessing a field on types that has been removed in Python 3.
:deprecated-itertools-function (W1651): *Accessing a deprecated function on the itertools module*
  Used when accessing a function on itertools that has been removed in Python 3.
:deprecated-string-function (W1649): *Accessing a deprecated function on the string module*
  Used when accessing a string function that has been deprecated in Python 3.
:deprecated-operator-function (W1657): *Accessing a removed attribute on the operator module*
  Used when accessing a field on operator module that has been removed in Python
  3.
:deprecated-sys-function (W1660): *Accessing a removed attribute on the sys module*
  Used when accessing a field on sys module that has been removed in Python 3.
:deprecated-urllib-function (W1658): *Accessing a removed attribute on the urllib module*
  Used when accessing a field on urllib module that has been removed or moved in
  Python 3.
:xreadlines-attribute (W1659): *Accessing a removed xreadlines attribute*
  Used when accessing the xreadlines() function on a file stream, removed in
  Python 3.
:metaclass-assignment (W1623): *Assigning to a class's __metaclass__ attribute*
  Used when a metaclass is specified by assigning to __metaclass__ (Python 3
  specifies the metaclass as a class statement argument)
:next-method-called (W1622): *Called a next() method on an object*
  Used when an object's next() method is called (Python 3 uses the next() built-
  in function)
:dict-iter-method (W1620): *Calling a dict.iter*() method*
  Used for calls to dict.iterkeys(), itervalues() or iteritems() (Python 3 lacks
  these methods)
:dict-view-method (W1621): *Calling a dict.view*() method*
  Used for calls to dict.viewkeys(), viewvalues() or viewitems() (Python 3 lacks
  these methods)
:exception-message-attribute (W1645): *Exception.message removed in Python 3*
  Used when the message attribute is accessed on an Exception. Use
  str(exception) instead.
:eq-without-hash (W1641): *Implementing __eq__ without also implementing __hash__*
  Used when a class implements __eq__ but not __hash__. In Python 2, objects get
  object.__hash__ as the default implementation, in Python 3 objects get None as
  their default __hash__ implementation if they also implement __eq__.
:indexing-exception (W1624): *Indexing exceptions will not work on Python 3*
  Indexing exceptions will not work on Python 3. Use `exception.args[index]`
  instead.
:bad-python3-import (W1648): *Module moved in Python 3*
  Used when importing a module that no longer exists in Python 3.
:raising-string (W1625): *Raising a string exception*
  Used when a string exception is raised. This will not work on Python 3.
:standarderror-builtin (W1611): *StandardError built-in referenced*
  Used when the StandardError built-in function is referenced (missing from
  Python 3)
:comprehension-escape (W1662): *Using a variable that was bound inside a comprehension*
  Emitted when using a variable, that was bound in a comprehension handler,
  outside of the comprehension itself. On Python 3 these variables will be
  deleted outside of the comprehension.
:exception-escape (W1661): *Using an exception object that was bound by an except handler*
  Emitted when using an exception, that was bound in an except handler, outside
  of the except handler. On Python 3 these exceptions will be deleted once they
  get out of the except handler.
:deprecated-str-translate-call (W1650): *Using str.translate with deprecated deletechars parameters*
  Used when using the deprecated deletechars parameters from str.translate. Use
  re.sub to remove the desired characters
:using-cmp-argument (W1640): *Using the cmp argument for list.sort / sorted*
  Using the cmp argument for list.sort or the sorted builtin should be avoided,
  since it was removed in Python 3. Using either `key` or `functools.cmp_to_key`
  should be preferred.
:cmp-method (W1630): *__cmp__ method defined*
  Used when a __cmp__ method is defined (method is not used by Python 3)
:coerce-method (W1614): *__coerce__ method defined*
  Used when a __coerce__ method is defined (method is not used by Python 3)
:delslice-method (W1615): *__delslice__ method defined*
  Used when a __delslice__ method is defined (method is not used by Python 3)
:div-method (W1642): *__div__ method defined*
  Used when a __div__ method is defined. Using `__truediv__` and setting__div__
  = __truediv__ should be preferred.(method is not used by Python 3)
:getslice-method (W1616): *__getslice__ method defined*
  Used when a __getslice__ method is defined (method is not used by Python 3)
:hex-method (W1628): *__hex__ method defined*
  Used when a __hex__ method is defined (method is not used by Python 3)
:idiv-method (W1643): *__idiv__ method defined*
  Used when an __idiv__ method is defined. Using `__itruediv__` and
  setting__idiv__ = __itruediv__ should be preferred.(method is not used by
  Python 3)
:nonzero-method (W1629): *__nonzero__ method defined*
  Used when a __nonzero__ method is defined (method is not used by Python 3)
:oct-method (W1627): *__oct__ method defined*
  Used when an __oct__ method is defined (method is not used by Python 3)
:rdiv-method (W1644): *__rdiv__ method defined*
  Used when a __rdiv__ method is defined. Using `__rtruediv__` and
  setting__rdiv__ = __rtruediv__ should be preferred.(method is not used by
  Python 3)
:setslice-method (W1617): *__setslice__ method defined*
  Used when a __setslice__ method is defined (method is not used by Python 3)
:apply-builtin (W1601): *apply built-in referenced*
  Used when the apply built-in function is referenced (missing from Python 3)
:basestring-builtin (W1602): *basestring built-in referenced*
  Used when the basestring built-in function is referenced (missing from Python
  3)
:buffer-builtin (W1603): *buffer built-in referenced*
  Used when the buffer built-in function is referenced (missing from Python 3)
:cmp-builtin (W1604): *cmp built-in referenced*
  Used when the cmp built-in function is referenced (missing from Python 3)
:coerce-builtin (W1605): *coerce built-in referenced*
  Used when the coerce built-in function is referenced (missing from Python 3)
:dict-items-not-iterating (W1654): *dict.items referenced when not iterating*
  Used when dict.items is referenced in a non-iterating context (returns an
  iterator in Python 3)
:dict-keys-not-iterating (W1655): *dict.keys referenced when not iterating*
  Used when dict.keys is referenced in a non-iterating context (returns an
  iterator in Python 3)
:dict-values-not-iterating (W1656): *dict.values referenced when not iterating*
  Used when dict.values is referenced in a non-iterating context (returns an
  iterator in Python 3)
:old-division (W1619): *division w/o __future__ statement*
  Used for non-floor division w/o a float literal or ``from __future__ import
  division`` (Python 3 returns a float for int division unconditionally)
:execfile-builtin (W1606): *execfile built-in referenced*
  Used when the execfile built-in function is referenced (missing from Python 3)
:file-builtin (W1607): *file built-in referenced*
  Used when the file built-in function is referenced (missing from Python 3)
:filter-builtin-not-iterating (W1639): *filter built-in referenced when not iterating*
  Used when the filter built-in is referenced in a non-iterating context
  (returns an iterator in Python 3)
:no-absolute-import (W1618): *import missing `from __future__ import absolute_import`*
  Used when an import is not accompanied by ``from __future__ import
  absolute_import`` (default behaviour in Python 3)
:input-builtin (W1632): *input built-in referenced*
  Used when the input built-in is referenced (backwards-incompatible semantics
  in Python 3)
:intern-builtin (W1634): *intern built-in referenced*
  Used when the intern built-in is referenced (Moved to sys.intern in Python 3)
:long-builtin (W1608): *long built-in referenced*
  Used when the long built-in function is referenced (missing from Python 3)
:map-builtin-not-iterating (W1636): *map built-in referenced when not iterating*
  Used when the map built-in is referenced in a non-iterating context (returns
  an iterator in Python 3)
:next-method-defined (W1653): *next method defined*
  Used when a next method is defined that would be an iterator in Python 2 but
  is treated as a normal function in Python 3.
:invalid-str-codec (W1646): *non-text encoding used in str.decode*
  Used when using str.encode or str.decode with a non-text encoding. Use codecs
  module to handle arbitrary codecs.
:range-builtin-not-iterating (W1638): *range built-in referenced when not iterating*
  Used when the range built-in is referenced in a non-iterating context (returns
  an iterator in Python 3)
:raw_input-builtin (W1609): *raw_input built-in referenced*
  Used when the raw_input built-in function is referenced (missing from Python
  3)
:reduce-builtin (W1610): *reduce built-in referenced*
  Used when the reduce built-in function is referenced (missing from Python 3)
:reload-builtin (W1626): *reload built-in referenced*
  Used when the reload built-in function is referenced (missing from Python 3).
  You can use instead imp.reload or importlib.reload.
:round-builtin (W1633): *round built-in referenced*
  Used when the round built-in is referenced (backwards-incompatible semantics
  in Python 3)
:sys-max-int (W1647): *sys.maxint removed in Python 3*
  Used when accessing sys.maxint. Use sys.maxsize instead.
:unichr-builtin (W1635): *unichr built-in referenced*
  Used when the unichr built-in is referenced (Use chr in Python 3)
:unicode-builtin (W1612): *unicode built-in referenced*
  Used when the unicode built-in function is referenced (missing from Python 3)
:xrange-builtin (W1613): *xrange built-in referenced*
  Used when the xrange built-in function is referenced (missing from Python 3)
:zip-builtin-not-iterating (W1637): *zip built-in referenced when not iterating*
  Used when the zip built-in is referenced in a non-iterating context (returns
  an iterator in Python 3)


Refactoring checker
~~~~~~~~~~~~~~~~~~~

Verbatim name of the checker is ``refactoring``.

Refactoring checker Options
^^^^^^^^^^^^^^^^^^^^^^^^^^^
:max-nested-blocks:
  Maximum number of nested blocks for function / method body

  Default: ``5``
:never-returning-functions:
  Complete name of functions that never returns. When checking for
  inconsistent-return-statements if a never returning function is called then
  it will be considered as an explicit return statement and no message will be
  printed.

  Default: ``sys.exit``

Refactoring checker Messages
^^^^^^^^^^^^^^^^^^^^^^^^^^^^
:simplify-boolean-expression (R1709): *Boolean expression may be simplified to %s*
  Emitted when redundant pre-python 2.5 ternary syntax is used.
:consider-using-in (R1714): *Consider merging these comparisons with "in" to %r*
  To check if a variable is equal to one of many values,combine the values into
  a tuple and check if the variable is contained "in" it instead of checking for
  equality against each of the values.This is faster and less verbose.
:consider-merging-isinstance (R1701): *Consider merging these isinstance calls to isinstance(%s, (%s))*
  Used when multiple consecutive isinstance calls can be merged into one.
:consider-using-dict-comprehension (R1717): *Consider using a dictionary comprehension*
  Although there is nothing syntactically wrong with this code, it is hard to
  read and can be simplified to a dict comprehension.Also it is faster since you
  don't need to create another transient list
:consider-using-set-comprehension (R1718): *Consider using a set comprehension*
  Although there is nothing syntactically wrong with this code, it is hard to
  read and can be simplified to a set comprehension.Also it is faster since you
  don't need to create another transient list
:consider-using-get (R1715): *Consider using dict.get for getting values from a dict if a key is present or a default if not*
  Using the builtin dict.get for getting a value from a dictionary if a key is
  present or a default if not, is simpler and considered more idiomatic,
  although sometimes a bit slower
:consider-using-join (R1713): *Consider using str.join(sequence) for concatenating strings from an iterable*
  Using str.join(sequence) is faster, uses less memory and increases readability
  compared to for-loop iteration.
:consider-using-ternary (R1706): *Consider using ternary (%s)*
  Used when one of known pre-python 2.5 ternary syntax is used.
:consider-swap-variables (R1712): *Consider using tuple unpacking for swapping variables*
  You do not have to use a temporary variable in order to swap variables. Using
  "tuple unpacking" to directly swap variables makes the intention more clear.
:trailing-comma-tuple (R1707): *Disallow trailing comma tuple*
  In Python, a tuple is actually created by the comma symbol, not by the
  parentheses. Unfortunately, one can actually create a tuple by misplacing a
  trailing comma, which can lead to potential weird bugs in your code. You
  should always use parentheses explicitly for creating a tuple.
:stop-iteration-return (R1708): *Do not raise StopIteration in generator, use return statement instead*
  According to PEP479, the raise of StopIteration to end the loop of a generator
  may lead to hard to find bugs. This PEP specify that raise StopIteration has
  to be replaced by a simple return statement
:inconsistent-return-statements (R1710): *Either all return statements in a function should return an expression, or none of them should.*
  According to PEP8, if any return statement returns an expression, any return
  statements where no value is returned should explicitly state this as return
  None, and an explicit return statement should be present at the end of the
  function (if reachable)
:redefined-argument-from-local (R1704): *Redefining argument with the local name %r*
  Used when a local name is redefining an argument, which might suggest a
  potential error. This is taken in account only for a handful of name binding
  operations, such as for iteration, with statement assignment and exception
  handler assignment.
:chained-comparison (R1716): *Simplify chained comparison between the operands*
  This message is emitted when pylint encounters boolean operation like"a < b
  and b < c", suggesting instead to refactor it to "a < b < c"
:simplifiable-if-expression (R1719): *The if expression can be replaced with %s*
  Used when an if expression can be replaced with 'bool(test)'.
:simplifiable-if-statement (R1703): *The if statement can be replaced with %s*
  Used when an if statement can be replaced with 'bool(test)'.
:too-many-nested-blocks (R1702): *Too many nested blocks (%s/%s)*
  Used when a function or a method has too many nested blocks. This makes the
  code less understandable and maintainable.
:no-else-raise (R1720): *Unnecessary "%s" after "raise"*
  Used in order to highlight an unnecessary block of code following an if
  containing a raise statement. As such, it will warn when it encounters an else
  following a chain of ifs, all of them containing a raise statement.
:no-else-return (R1705): *Unnecessary "%s" after "return"*
  Used in order to highlight an unnecessary block of code following an if
  containing a return statement. As such, it will warn when it encounters an
  else following a chain of ifs, all of them containing a return statement.
:useless-return (R1711): *Useless return at end of function or method*
  Emitted when a single "return" or "return None" statement is found at the end
  of function or method definition. This statement can safely be removed because
  Python will implicitly return None
:unneeded-not (C0113): *Consider changing "%s" to "%s"*
  Used when a boolean expression contains an unneeded negation.
:consider-iterating-dictionary (C0201): *Consider iterating the dictionary directly instead of calling .keys()*
  Emitted when the keys of a dictionary are iterated through the .keys() method.
  It is enough to just iterate through the dictionary itself, as in "for key in
  dictionary".
:consider-using-enumerate (C0200): *Consider using enumerate instead of iterating with range and len*
  Emitted when code that iterates with range and len is encountered. Such code
  can be simplified by using the enumerate builtin.
:len-as-condition (C1801): *Do not use `len(SEQUENCE)` to determine if a sequence is empty*
  Used when Pylint detects that len(sequence) is being used inside a condition
  to determine if a sequence is empty. Instead of comparing the length to 0,
  rely on the fact that empty sequences are false.


Similarities checker
~~~~~~~~~~~~~~~~~~~~

Verbatim name of the checker is ``similarities``.

Similarities checker Options
^^^^^^^^^^^^^^^^^^^^^^^^^^^^
:min-similarity-lines:
  Minimum lines number of a similarity.

  Default: ``4``
:ignore-comments:
  Ignore comments when computing similarities.

  Default: ``yes``
:ignore-docstrings:
  Ignore docstrings when computing similarities.

  Default: ``yes``
:ignore-imports:
  Ignore imports when computing similarities.

Similarities checker Messages
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
:duplicate-code (R0801): *Similar lines in %s files*
  Indicates that a set of similar lines has been detected among multiple file.
  This usually means that the code should be refactored to avoid this
  duplication.

Similarities checker Reports
^^^^^^^^^^^^^^^^^^^^^^^^^^^^
:RP0801: Duplication


Spelling checker
~~~~~~~~~~~~~~~~

Verbatim name of the checker is ``spelling``.

Spelling checker Options
^^^^^^^^^^^^^^^^^^^^^^^^
:spelling-dict:
  Spelling dictionary name. Available dictionaries: none. To make it working
  install python-enchant package..
:spelling-ignore-words:
  List of comma separated words that should not be checked.
:spelling-private-dict-file:
  A path to a file that contains private dictionary; one word per line.
:spelling-store-unknown-words:
  Tells whether to store unknown words to indicated private dictionary in
  --spelling-private-dict-file option instead of raising a message.
:max-spelling-suggestions:
  Limits count of emitted suggestions for spelling mistakes.

  Default: ``4``

Spelling checker Messages
^^^^^^^^^^^^^^^^^^^^^^^^^
:invalid-characters-in-docstring (C0403): *Invalid characters %r in a docstring*
  Used when a word in docstring cannot be checked by enchant.
:wrong-spelling-in-comment (C0401): *Wrong spelling of a word '%s' in a comment:*
  Used when a word in comment is not spelled correctly.
:wrong-spelling-in-docstring (C0402): *Wrong spelling of a word '%s' in a docstring:*
  Used when a word in docstring is not spelled correctly.


Stdlib checker
~~~~~~~~~~~~~~

Verbatim name of the checker is ``stdlib``.

Stdlib checker Messages
^^^^^^^^^^^^^^^^^^^^^^^
:invalid-envvar-value (E1507): *%s does not support %s type argument*
  Env manipulation functions support only string type arguments. See
  https://docs.python.org/3/library/os.html#os.getenv.
:bad-open-mode (W1501): *"%s" is not a valid mode for open.*
  Python supports: r, w, a[, x] modes with b, +, and U (only with r) options.
  See http://docs.python.org/2/library/functions.html#open
:invalid-envvar-default (W1508): *%s default type is %s. Expected str or None.*
  Env manipulation functions return None or str values. Supplying anything
  different as a default may cause bugs. See
  https://docs.python.org/3/library/os.html#os.getenv.
:redundant-unittest-assert (W1503): *Redundant use of %s with constant value %r*
  The first argument of assertTrue and assertFalse is a condition. If a constant
  is passed as parameter, that condition will be always true. In this case a
  warning should be emitted.
:shallow-copy-environ (W1507): *Using copy.copy(os.environ). Use os.environ.copy() instead.*
  os.environ is not a dict object but proxy object, so shallow copy has still
  effects on original object. See https://bugs.python.org/issue15373 for
  reference.
:boolean-datetime (W1502): *Using datetime.time in a boolean context.*
  Using datetime.time in a boolean context can hide subtle bugs when the time
  they represent matches midnight UTC. This behaviour was fixed in Python 3.5.
  See http://bugs.python.org/issue13936 for reference. This message can't be
  emitted when using Python >= 3.5.
:deprecated-method (W1505): *Using deprecated method %s()*
  The method is marked as deprecated and will be removed in a future version of
  Python. Consider looking for an alternative in the documentation.
:subprocess-popen-preexec-fn (W1509): *Using preexec_fn keyword which may be unsafe in the presence of threads*
  The preexec_fn parameter is not safe to use in the presence of threads in your
  application. The child process could deadlock before exec is called. If you
  must use it, keep it trivial! Minimize the number of libraries you call
  into.https://docs.python.org/3/library/subprocess.html#popen-constructor
:bad-thread-instantiation (W1506): *threading.Thread needs the target function*
  The warning is emitted when a threading.Thread class is instantiated without
  the target function being passed. By default, the first parameter is the group
  param, not the target param.


String checker
~~~~~~~~~~~~~~

Verbatim name of the checker is ``string``.

String checker Options
^^^^^^^^^^^^^^^^^^^^^^
:check-str-concat-over-line-jumps:
  This flag controls whether the implicit-str-concat-in-sequence should
  generate a warning on implicit string concatenation in sequences defined over
  several lines.

String checker Messages
^^^^^^^^^^^^^^^^^^^^^^^
:bad-string-format-type (E1307): *Argument %r does not match format type %r*
  Used when a type required by format string is not suitable for actual argument
  type
:format-needs-mapping (E1303): *Expected mapping for format string, not %s*
  Used when a format string that uses named conversion specifiers is used with
  an argument that is not a mapping.
:truncated-format-string (E1301): *Format string ends in middle of conversion specifier*
  Used when a format string terminates before the end of a conversion specifier.
:missing-format-string-key (E1304): *Missing key %r in format string dictionary*
  Used when a format string that uses named conversion specifiers is used with a
  dictionary that doesn't contain all the keys required by the format string.
:mixed-format-string (E1302): *Mixing named and unnamed conversion specifiers in format string*
  Used when a format string contains both named (e.g. '%(foo)d') and unnamed
  (e.g. '%d') conversion specifiers. This is also used when a named conversion
  specifier contains * for the minimum field width and/or precision.
:too-few-format-args (E1306): *Not enough arguments for format string*
  Used when a format string that uses unnamed conversion specifiers is given too
  few arguments
:bad-str-strip-call (E1310): *Suspicious argument in %s.%s call*
  The argument to a str.{l,r,}strip call contains a duplicate character,
:too-many-format-args (E1305): *Too many arguments for format string*
  Used when a format string that uses unnamed conversion specifiers is given too
  many arguments.
:bad-format-character (E1300): *Unsupported format character %r (%#02x) at index %d*
  Used when an unsupported format character is used in a format string.
:anomalous-unicode-escape-in-string (W1402): *Anomalous Unicode escape in byte string: '%s'. String constant might be missing an r or u prefix.*
  Used when an escape like \u is encountered in a byte string where it has no
  effect.
:anomalous-backslash-in-string (W1401): *Anomalous backslash in string: '%s'. String constant might be missing an r prefix.*
  Used when a backslash is in a literal string but not as an escape.
:duplicate-string-formatting-argument (W1308): *Duplicate string formatting argument %r, consider passing as named argument*
  Used when we detect that a string formatting is repeating an argument instead
  of using named string arguments
:format-combined-specification (W1305): *Format string contains both automatic field numbering and manual field specification*
  Used when a PEP 3101 format string contains both automatic field numbering
  (e.g. '{}') and manual field specification (e.g. '{0}').
:bad-format-string-key (W1300): *Format string dictionary key should be a string, not %s*
  Used when a format string that uses named conversion specifiers is used with a
  dictionary whose keys are not all strings.
:implicit-str-concat-in-sequence (W1403): *Implicit string concatenation found in %s*
  String literals are implicitly concatenated in a literal iterable definition :
  maybe a comma is missing ?
:bad-format-string (W1302): *Invalid format string*
  Used when a PEP 3101 format string is invalid.
:missing-format-attribute (W1306): *Missing format attribute %r in format specifier %r*
  Used when a PEP 3101 format string uses an attribute specifier ({0.length}),
  but the argument passed for formatting doesn't have that attribute.
:missing-format-argument-key (W1303): *Missing keyword argument %r for format string*
  Used when a PEP 3101 format string that uses named fields doesn't receive one
  or more required keywords.
:unused-format-string-argument (W1304): *Unused format argument %r*
  Used when a PEP 3101 format string that uses named fields is used with an
  argument that is not required by the format string.
:unused-format-string-key (W1301): *Unused key %r in format string dictionary*
  Used when a format string that uses named conversion specifiers is used with a
  dictionary that contains keys not required by the format string.
:invalid-format-index (W1307): *Using invalid lookup key %r in format specifier %r*
  Used when a PEP 3101 format string uses a lookup specifier ({a[1]}), but the
  argument passed for formatting doesn't contain or doesn't have that key as an
  attribute.


Typecheck checker
~~~~~~~~~~~~~~~~~

Verbatim name of the checker is ``typecheck``.

Typecheck checker Options
^^^^^^^^^^^^^^^^^^^^^^^^^
:ignore-on-opaque-inference:
  This flag controls whether pylint should warn about no-member and similar
  checks whenever an opaque object is returned when inferring. The inference
  can return multiple potential results while evaluating a Python object, but
  some branches might not be evaluated, which results in partial inference. In
  that case, it might be useful to still emit no-member and other checks for
  the rest of the inferred objects.

  Default: ``yes``
:ignore-mixin-members:
  Tells whether missing members accessed in mixin class should be ignored. A
  mixin class is detected if its name ends with "mixin" (case insensitive).

  Default: ``yes``
:ignore-none:
  Tells whether to warn about missing members when the owner of the attribute
  is inferred to be None.

  Default: ``yes``
:ignored-modules:
  List of module names for which member attributes should not be checked
  (useful for modules/projects where namespaces are manipulated during runtime
  and thus existing member attributes cannot be deduced by static analysis. It
  supports qualified module names, as well as Unix pattern matching.
:ignored-classes:
  List of class names for which member attributes should not be checked (useful
  for classes with dynamically set attributes). This supports the use of
  qualified names.

  Default: ``optparse.Values,thread._local,_thread._local``
:generated-members:
  List of members which are set dynamically and missed by pylint inference
  system, and so shouldn't trigger E1101 when accessed. Python regular
  expressions are accepted.
:contextmanager-decorators:
  List of decorators that produce context managers, such as
  contextlib.contextmanager. Add to this list to register other decorators that
  produce valid context managers.

  Default: ``contextlib.contextmanager``
:missing-member-hint-distance:
  The minimum edit distance a name should have in order to be considered a
  similar match for a missing member name.

  Default: ``1``
:missing-member-max-choices:
  The total number of similar names that should be taken in consideration when
  showing a hint for a missing member.

  Default: ``1``
:missing-member-hint:
  Show a hint with possible names when a member name was not found. The aspect
  of finding the hint is based on edit distance.

  Default: ``yes``

Typecheck checker Messages
^^^^^^^^^^^^^^^^^^^^^^^^^^
:unsupported-assignment-operation (E1137): *%r does not support item assignment*
  Emitted when an object does not support item assignment (i.e. doesn't define
  __setitem__ method).
:unsupported-delete-operation (E1138): *%r does not support item deletion*
  Emitted when an object does not support item deletion (i.e. doesn't define
  __delitem__ method).
:invalid-unary-operand-type (E1130):
  Emitted when a unary operand is used on an object which does not support this
  type of operation.
:unsupported-binary-operation (E1131):
  Emitted when a binary arithmetic operation between two operands is not
  supported.
:no-member (E1101): *%s %r has no %r member%s*
  Used when a variable is accessed for an unexistent member.
:not-callable (E1102): *%s is not callable*
  Used when an object being called has been inferred to a non callable object.
:redundant-keyword-arg (E1124): *Argument %r passed by position and keyword in %s call*
  Used when a function call would result in assigning multiple values to a
  function parameter, one value from a positional argument and one from a
  keyword argument.
:assignment-from-no-return (E1111): *Assigning result of a function call, where the function has no return*
  Used when an assignment is done on a function call but the inferred function
  doesn't return anything.
:assignment-from-none (E1128): *Assigning result of a function call, where the function returns None*
  Used when an assignment is done on a function call but the inferred function
  returns nothing but None.
:not-context-manager (E1129): *Context manager '%s' doesn't implement __enter__ and __exit__.*
  Used when an instance in a with statement doesn't implement the context
  manager protocol(__enter__/__exit__).
:unhashable-dict-key (E1140): *Dict key is unhashable*
  Emitted when a dict key is not hashable (i.e. doesn't define __hash__ method).
:repeated-keyword (E1132): *Got multiple values for keyword argument %r in function call*
  Emitted when a function call got multiple values for a keyword.
:invalid-metaclass (E1139): *Invalid metaclass %r used*
  Emitted whenever we can detect that a class is using, as a metaclass,
  something which might be invalid for using as a metaclass.
:missing-kwoa (E1125): *Missing mandatory keyword argument %r in %s call*
  Used when a function call does not pass a mandatory keyword-only argument.
:no-value-for-parameter (E1120): *No value for argument %s in %s call*
  Used when a function call passes too few arguments.
:not-an-iterable (E1133): *Non-iterable value %s is used in an iterating context*
  Used when a non-iterable value is used in place where iterable is expected
:not-a-mapping (E1134): *Non-mapping value %s is used in a mapping context*
  Used when a non-mapping value is used in place where mapping is expected
:invalid-sequence-index (E1126): *Sequence index is not an int, slice, or instance with __index__*
  Used when a sequence type is indexed with an invalid type. Valid types are
  ints, slices, and objects with an __index__ method.
:invalid-slice-index (E1127): *Slice index is not an int, None, or instance with __index__*
  Used when a slice index is not an integer, None, or an object with an
  __index__ method.
:too-many-function-args (E1121): *Too many positional arguments for %s call*
  Used when a function call passes too many positional arguments.
:unexpected-keyword-arg (E1123): *Unexpected keyword argument %r in %s call*
  Used when a function call passes a keyword argument that doesn't correspond to
  one of the function's parameter names.
:unsupported-membership-test (E1135): *Value '%s' doesn't support membership test*
  Emitted when an instance in membership test expression doesn't implement
  membership protocol (__contains__/__iter__/__getitem__).
:unsubscriptable-object (E1136): *Value '%s' is unsubscriptable*
  Emitted when a subscripted value doesn't support subscription (i.e. doesn't
  define __getitem__ method or __class_getitem__ for a class).
:keyword-arg-before-vararg (W1113): *Keyword argument before variable positional arguments list in the definition of %s function*
  When defining a keyword argument before variable positional arguments, one can
  end up in having multiple values passed for the aforementioned parameter in
  case the method is called with keyword arguments.
:c-extension-no-member (I1101): *%s %r has no %r member%s, but source is unavailable. Consider adding this module to extension-pkg-whitelist if you want to perform analysis based on run-time introspection of living objects.*
  Used when a variable is accessed for non-existent member of C extension. Due
  to unavailability of source static analysis is impossible, but it may be
  performed by introspecting living objects in run-time.


Variables checker
~~~~~~~~~~~~~~~~~

Verbatim name of the checker is ``variables``.

Variables checker Options
^^^^^^^^^^^^^^^^^^^^^^^^^
:init-import:
  Tells whether we should check for unused import in __init__ files.
:dummy-variables-rgx:
  A regular expression matching the name of dummy variables (i.e. expected to
  not be used).

  Default: ``_+$|(_[a-zA-Z0-9_]*[a-zA-Z0-9]+?$)|dummy|^ignored_|^unused_``
:additional-builtins:
  List of additional names supposed to be defined in builtins. Remember that
  you should avoid defining new builtins when possible.
:callbacks:
  List of strings which can identify a callback function by name. A callback
  name must start or end with one of those strings.

  Default: ``cb_,_cb``
:redefining-builtins-modules:
  List of qualified module names which can have objects that can redefine
  builtins.

  Default: ``six.moves,past.builtins,future.builtins,builtins,io``
:ignored-argument-names:
  Argument names that match this expression will be ignored. Default to name
  with leading underscore.

  Default: ``_.*|^ignored_|^unused_``
:allow-global-unused-variables:
  Tells whether unused global variables should be treated as a violation.

  Default: ``yes``

Variables checker Messages
^^^^^^^^^^^^^^^^^^^^^^^^^^
:unpacking-non-sequence (E0633): *Attempting to unpack a non-sequence%s*
  Used when something which is not a sequence is used in an unpack assignment
:invalid-all-object (E0604): *Invalid object %r in __all__, must contain only strings*
  Used when an invalid (non-string) object occurs in __all__.
:no-name-in-module (E0611): *No name %r in module %r*
  Used when a name cannot be found in a module.
:undefined-variable (E0602): *Undefined variable %r*
  Used when an undefined variable is accessed.
:undefined-all-variable (E0603): *Undefined variable name %r in __all__*
  Used when an undefined variable name is referenced in __all__.
:used-before-assignment (E0601): *Using variable %r before assignment*
  Used when a local variable is accessed before its assignment.
:cell-var-from-loop (W0640): *Cell variable %s defined in loop*
  A variable used in a closure is defined in a loop. This will result in all
  closures using the same value for the closed-over variable.
:global-variable-undefined (W0601): *Global variable %r undefined at the module level*
  Used when a variable is defined through the "global" statement but the
  variable is not defined in the module scope.
:self-cls-assignment (W0642): *Invalid assignment to %s in method*
  Invalid assignment to self or cls in instance or class method respectively.
:unbalanced-tuple-unpacking (W0632): *Possible unbalanced tuple unpacking with sequence%s: left side has %d label(s), right side has %d value(s)*
  Used when there is an unbalanced tuple unpacking in assignment
:possibly-unused-variable (W0641): *Possibly unused variable %r*
  Used when a variable is defined but might not be used. The possibility comes
  from the fact that locals() might be used, which could consume or not the said
  variable
:redefined-builtin (W0622): *Redefining built-in %r*
  Used when a variable or function override a built-in.
:redefine-in-handler (W0623): *Redefining name %r from %s in exception handler*
  Used when an exception handler assigns the exception to an existing name
:redefined-outer-name (W0621): *Redefining name %r from outer scope (line %s)*
  Used when a variable's name hides a name defined in the outer scope.
:unused-import (W0611): *Unused %s*
  Used when an imported module or variable is not used.
:unused-argument (W0613): *Unused argument %r*
  Used when a function or method argument is not used.
:unused-wildcard-import (W0614): *Unused import %s from wildcard import*
  Used when an imported module or variable is not used from a `'from X import
  *'` style import.
:unused-variable (W0612): *Unused variable %r*
  Used when a variable is defined but not used.
:global-variable-not-assigned (W0602): *Using global for %r but no assignment is done*
  Used when a variable is defined through the "global" statement but no
  assignment to this variable is done.
:undefined-loop-variable (W0631): *Using possibly undefined loop variable %r*
  Used when a loop variable (i.e. defined by a for loop or a list comprehension
  or a generator expression) is used outside the loop.
:global-statement (W0603): *Using the global statement*
  Used when you use the "global" statement to update a global variable. Pylint
  just try to discourage this usage. That doesn't mean you cannot use it !
:global-at-module-level (W0604): *Using the global statement at the module level*
  Used when you use the "global" statement at the module level since it has no
  effect