pylint
pylint documentation
- Version in MegaLinter: 2.14.3
- Visit Official Web Site
- See How to configure pylint rules
- If custom
.python-lintconfig file is not found, .python-lint will be used
- If custom
- See How to disable pylint rules in files
- See Index of problems detected by pylint
Configuration in MegaLinter
- Enable pylint by adding
PYTHON_PYLINTin ENABLE_LINTERS variable - Disable pylint by adding
PYTHON_PYLINTin DISABLE_LINTERS variable
| Variable | Description | Default value |
|---|---|---|
| PYTHON_PYLINT_ARGUMENTS | User custom arguments to add in linter CLI call Ex: -s --foo "bar" |
|
| PYTHON_PYLINT_FILTER_REGEX_INCLUDE | Custom regex including filter Ex: (src\|lib) |
Include every file |
| PYTHON_PYLINT_FILTER_REGEX_EXCLUDE | Custom regex excluding filter Ex: (test\|examples) |
Exclude no file |
| PYTHON_PYLINT_CLI_LINT_MODE | Override default CLI lint mode - file: Calls the linter for each file- list_of_files: Call the linter with the list of files as argument- project: Call the linter from the root of the project |
list_of_files |
| PYTHON_PYLINT_FILE_EXTENSIONS | Allowed file extensions. "*" matches any extension, "" matches empty extension. Empty list excludes all filesEx: [".py", ""] |
[".py"] |
| PYTHON_PYLINT_FILE_NAMES_REGEX | File name regex filters. Regular expression list for filtering files by their base names using regex full match. Empty list includes all files Ex: ["Dockerfile(-.+)?", "Jenkinsfile"] |
Include every file |
| PYTHON_PYLINT_PRE_COMMANDS | List of bash commands to run before the linter | None |
| PYTHON_PYLINT_POST_COMMANDS | List of bash commands to run after the linter | None |
| PYTHON_PYLINT_CONFIG_FILE | pylint configuration file nameUse LINTER_DEFAULT to let the linter find it |
.python-lint |
| PYTHON_PYLINT_RULES_PATH | Path where to find linter configuration file | Workspace folder, then MegaLinter default rules |
| PYTHON_PYLINT_DISABLE_ERRORS | Run linter but consider errors as warnings | false |
| PYTHON_PYLINT_DISABLE_ERRORS_IF_LESS_THAN | Maximum number of errors allowed | 0 |
IDE Integration
Use pylint in your favorite IDE to catch errors before MegaLinter !
| IDE | Extension Name | Install | |
|---|---|---|---|
| Eclipse | PyLint | Visit Web Site | |
| IDEA | PyCharm (Native Support) | Visit Web Site | |
| vim | pylint.vim | Visit Web Site | |
| visual_studio | Native Support | Visit Web Site | |
| Visual Studio Code | Native Support | Visit Web Site |
MegaLinter Flavours
This linter is available in the following flavours
| Flavor | Description | Embedded linters | Info | |
|---|---|---|---|---|
 |
all | Default MegaLinter Flavor | 101 |   |
| python | Optimized for PYTHON based projects | 50 |   |
Behind the scenes
How are identified applicable files
- File extensions:
.py
How the linting is performed
- pylint is called once with the list of files as arguments
Example calls
pylint myfile.py
pylint --rcfile .python-lint myfile.py
Help content
usage: pylint [options]
optional arguments:
-h, --help show this help message and exit
Commands:
Options which are actually commands. Options in this group are mutually exclusive.
--rcfile RCFILE Specify a configuration file to load.
--output OUTPUT Specify an output file.
--help-msg HELP_MSG [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 Display a list of all pylint's messages divided by
whether they are emittable with the given interpreter.
--list-msgs-enabled Display a list of what messages are enabled, disabled
and non-emittable with the given configuration.
--list-groups List pylint's message groups.
--list-conf-levels Generate pylint's confidence levels.
--list-extensions List available extensions.
--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-toml-config
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. The config is in the .toml format.
--long-help Show more verbose help.
Main:
--init-hook INIT_HOOK
Python code to execute, usually for sys.path
manipulation such as pygtk.require().
--errors-only, -E In error mode, messages with a category besides ERROR
or FATAL are suppressed, and no reports are done by
default. Error mode is compatible with disabling
specific errors.
--verbose , -v In verbose mode, extra non-checker-related info will
be displayed.
--enable-all-extensions
Load and enable all available extensions. Use --list-
extensions to see a list all available extensions.
--ignore <file>[,<file>...]
Files or directories to be skipped. They should be
base names, not paths. (default: ('CVS',))
--ignore-patterns <pattern>[,<pattern>...]
Files or directories matching the regex patterns are
skipped. The regex matches against base names, not
paths. The default value ignores Emacs file locks
(default: (re.compile('^\\.#'),))
--ignore-paths <pattern>[,<pattern>...]
Add files or directories matching the regex patterns
to the ignore-list. The regex matches against paths
and can be in Posix or Windows format. (default: [])
--persistent <y or n>
Pickle collected data for later comparisons. (default:
True)
--load-plugins <modules>
List of plugins (as comma separated values of python
module names) to load, usually to register additional
checkers. (default: ())
--fail-under <score> Specify a score threshold to be exceeded before
program exits with error. (default: 10)
--fail-on <msg ids> Return non-zero exit code if any of these
messages/categories are detected, even if score is
above --fail-under value. Syntax same as enable.
Messages specified are enabled, while categories only
check already-enabled messages. (default: )
--jobs <n-processes>, -j <n-processes>
Use multiple processes to speed up Pylint. Specifying
0 will auto-detect the number of processors available
to use. (default: 1)
--limit-inference-results <number-of-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-allow-list <pkg[,pkg]>
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. (default: [])
--extension-pkg-whitelist <pkg[,pkg]>
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. (This is an alternative name to
extension-pkg-allow-list for backward compatibility.)
(default: [])
--suggestion-mode <y or n>
When enabled, pylint would attempt to guess common
misconfiguration and emit user-friendly hints instead
of false-positive error messages. (default: True)
--exit-zero Always return a 0 (non-error) status code, even if
lint errors are found. This is primarily useful in
continuous integration scripts. (default: False)
--from-stdin Interpret the stdin as a python script, whose filename
needs to be passed as the module_or_package argument.
(default: False)
--recursive <yn> Discover python modules and packages in the file
system subtree. (default: False)
--py-version <py_version>
Minimum Python version to use for version dependent
checks. Will default to the version used to run
pylint. (default: (3, 9))
--ignored-modules <module names>
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. (default: ())
--analyse-fallback-blocks <y or n>
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. (default: False)
Reports:
Options related to output formatting and reporting
--output-format <format>, -f <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.
--reports <y or n>, -r <y or n>
Tells whether to display a full report or only the
messages. (default: False)
--evaluation <python_expression>
Python expression which should return a score less
than or equal to 10. You have access to the variables
'fatal', 'error', 'warning', 'refactor', 'convention',
and 'info' which contain the number of messages in
each category, as well as 'statement' which is the
total number of statements analyzed. This score is
used by the global evaluation report (RP0004).
(default: max(0, 0 if fatal else 10.0 - ((float(5 *
error + warning + refactor + convention) / statement)
* 10)))
--score <y or n>, -s <y or n>
Activate the evaluation score. (default: True)
--msg-template <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. (default: )
Messages control:
Options controlling analysis messages
--confidence <levels>
Only show warnings with the listed confidence levels.
Leave empty to show all. Valid levels: HIGH,
CONTROL_FLOW, INFERENCE, INFERENCE_FAILURE, UNDEFINED.
(default: ['HIGH', 'CONTROL_FLOW', 'INFERENCE',
'INFERENCE_FAILURE', 'UNDEFINED'])
--enable <msg ids>, -e <msg ids>
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.
--disable <msg ids>, -d <msg ids>
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 re-enable 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".
String:
Check string literals.
--check-str-concat-over-line-jumps <y or n>
This flag controls whether the implicit-str-concat
should generate a warning on implicit string
concatenation in sequences defined over several lines.
(default: False)
--check-quote-consistency <y or n>
This flag controls whether inconsistent-quotes
generates a warning when the character used as a quote
delimiter is used inconsistently within a module.
(default: False)
Exceptions:
Exception related checks.
--overgeneral-exceptions <comma-separated class names>
Exceptions that will emit a warning when caught.
(default: ('BaseException', 'Exception'))
Refactoring:
Looks for code which can be refactored.
--max-nested-blocks <int>
Maximum number of nested blocks for function / method
body (default: 5)
--never-returning-functions <members names>
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',
'argparse.parse_error'))
Format:
Formatting checker.
--max-line-length <int>
Maximum number of characters on a single line.
(default: 100)
--ignore-long-lines <regexp>
Regexp for a line that is allowed to be longer than
the limit. (default: ^\s*(# )?<?https?://\S+>?$)
--single-line-if-stmt <y or n>
Allow the body of an if to be on the same line as the
test if there is no else. (default: False)
--single-line-class-stmt <y or n>
Allow the body of a class to be on the same line as
the declaration if body contains single statement.
(default: False)
--max-module-lines <int>
Maximum number of lines in a module. (default: 1000)
--indent-string <string>
String used as indentation unit. This is usually " "
(4 spaces) or " " (1 tab). (default: )
--indent-after-paren <int>
Number of spaces of indent required inside a hanging
or continued line. (default: 4)
--expected-line-ending-format <empty or LF or CRLF>
Expected format of line ending, e.g. empty (any line
ending), LF or CRLF. (default: )
Typecheck:
Try to find bugs in the code using type inference.
--ignore-on-opaque-inference <y or n>
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:
True)
--mixin-class-rgx <regexp>
Regex pattern to define which classes are considered
mixins. (default: .*[Mm]ixin)
--ignore-mixin-members <y or n>
Tells whether missing members accessed in mixin class
should be ignored. A class is considered mixin if its
name matches the mixin-class-rgx option. (default:
True)
--ignored-checks-for-mixins <list of messages names>
List of symbolic message names to ignore for Mixin
members. (default: ['no-member', 'not-async-context-
manager', 'not-context-manager', 'attribute-defined-
outside-init'])
--ignore-none <y or n>
Tells whether to warn about missing members when the
owner of the attribute is inferred to be None.
(default: True)
--ignored-classes <members names>
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', 'argparse.Namespace'))
--generated-members <members names>
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. (default: ())
--contextmanager-decorators <decorator names>
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 <member hint edit 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 <member hint 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 <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: True)
--signature-mutators <decorator names>
List of decorators that change the signature of a
decorated function. (default: [])
Variables:
BaseChecker for variables.
--init-import <y or n>
Tells whether we should check for unused import in
__init__ files. (default: False)
--dummy-variables-rgx <regexp>
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_|^unus
ed_)
--additional-builtins <comma separated list>
List of additional names supposed to be defined in
builtins. Remember that you should avoid defining new
builtins when possible. (default: ())
--callbacks <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 <comma separated list>
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 <regexp>
Argument names that match this expression will be
ignored. Default to name with leading underscore.
(default: re.compile('_.*|^ignored_|^unused_'))
--allow-global-unused-variables <y or n>
Tells whether unused global variables should be
treated as a violation. (default: True)
--allowed-redefined-builtins <comma separated list>
List of names allowed to shadow builtins (default: ())
Spelling:
Check spelling in comments and docstrings.
--spelling-dict <dict name>
Spelling dictionary name. Available dictionaries:
none. To make it work, install the 'python-enchant'
package. (default: )
--spelling-ignore-words <comma separated words>
List of comma separated words that should not be
checked. (default: )
--spelling-private-dict-file <path to file>
A path to a file that contains the private dictionary;
one word per line. (default: )
--spelling-store-unknown-words <y or n>
Tells whether to store unknown words to the private
dictionary (see the --spelling-private-dict-file
option) instead of raising a message. (default: n)
--max-spelling-suggestions N
Limits count of emitted suggestions for spelling
mistakes. (default: 4)
--spelling-ignore-comment-directives <comma separated words>
List of comma separated words that should be
considered directives if they appear at the beginning
of a comment and should not be checked. (default: fmt:
on,fmt: off,noqa:,noqa,nosec,isort:skip,mypy:)
Classes:
Checker for class nodes.
--defining-attr-methods <method names>
List of method names used to declare (i.e. assign)
instance attributes. (default: ('__init__', '__new__',
'setUp', '__post_init__'))
--valid-classmethod-first-arg <argument names>
List of valid names for the first argument in a class
method. (default: ('cls',))
--valid-metaclass-classmethod-first-arg <argument names>
List of valid names for the first argument in a
metaclass class method. (default: ('cls',))
--exclude-protected <protected access exclusions>
List of member names, which should be excluded from
the protected access warning. (default: ('_asdict',
'_fields', '_replace', '_source', '_make'))
--check-protected-access-in-special-methods <y or n>
Warn about protected attribute access inside special
methods (default: False)
Design:
Checker of potential misdesigns.
--max-args <int> Maximum number of arguments for function / method.
(default: 5)
--max-locals <int> Maximum number of locals for function / method body.
(default: 15)
--max-returns <int> Maximum number of return / yield for function / method
body. (default: 6)
--max-branches <int> Maximum number of branch for function / method body.
(default: 12)
--max-statements <int>
Maximum number of statements in function / method
body. (default: 50)
--max-parents <num> Maximum number of parents for a class (see R0901).
(default: 7)
--ignored-parents <comma separated list of class names>
List of qualified class names to ignore when counting
class parents (see R0901) (default: ())
--max-attributes <num>
Maximum number of attributes for a class (see R0902).
(default: 7)
--min-public-methods <num>
Minimum number of public methods for a class (see
R0903). (default: 2)
--max-public-methods <num>
Maximum number of public methods for a class (see
R0904). (default: 20)
--max-bool-expr <num>
Maximum number of boolean expressions in an if
statement (see R0916). (default: 5)
--exclude-too-few-public-methods <pattern>[,<pattern>...]
List of regular expressions of class ancestor names to
ignore when counting public methods (see R0903)
(default: [])
Basic:
--good-names <names> Good variable names which should always be accepted,
separated by a comma. (default: ('i', 'j', 'k', 'ex',
'Run', '_'))
--good-names-rgxs <names>
Good variable names regexes, separated by a comma. If
names match any regex, they will always be accepted
(default: )
--bad-names <names> Bad variable names which should always be refused,
separated by a comma. (default: ('foo', 'bar', 'baz',
'toto', 'tutu', 'tata'))
--bad-names-rgxs <names>
Bad variable names regexes, separated by a comma. If
names match any regex, they will always be refused
(default: )
--name-group <name1:name2>
Colon-delimited sets of names that determine each
other's naming style when the name regexes allow
several styles. (default: ())
--include-naming-hint <y or n>
Include a hint for the correct naming format with
invalid-name. (default: False)
--property-classes <decorator names>
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 <style>
Naming style matching correct argument names.
(default: snake_case)
--argument-rgx <regexp>
Regular expression matching correct argument names.
Overrides argument-naming-style. If left empty,
argument names will be checked with the set naming
style. (default: None)
--attr-naming-style <style>
Naming style matching correct attribute names.
(default: snake_case)
--attr-rgx <regexp> Regular expression matching correct attribute names.
Overrides attr-naming-style. If left empty, attribute
names will be checked with the set naming style.
(default: None)
--class-naming-style <style>
Naming style matching correct class names. (default:
PascalCase)
--class-rgx <regexp> Regular expression matching correct class names.
Overrides class-naming-style. If left empty, class
names will be checked with the set naming style.
(default: None)
--class-attribute-naming-style <style>
Naming style matching correct class attribute names.
(default: any)
--class-attribute-rgx <regexp>
Regular expression matching correct class attribute
names. Overrides class-attribute-naming-style. If left
empty, class attribute names will be checked with the
set naming style. (default: None)
--class-const-naming-style <style>
Naming style matching correct class constant names.
(default: UPPER_CASE)
--class-const-rgx <regexp>
Regular expression matching correct class constant
names. Overrides class-const-naming-style. If left
empty, class constant names will be checked with the
set naming style. (default: None)
--const-naming-style <style>
Naming style matching correct constant names.
(default: UPPER_CASE)
--const-rgx <regexp> Regular expression matching correct constant names.
Overrides const-naming-style. If left empty, constant
names will be checked with the set naming style.
(default: None)
--function-naming-style <style>
Naming style matching correct function names.
(default: snake_case)
--function-rgx <regexp>
Regular expression matching correct function names.
Overrides function-naming-style. If left empty,
function names will be checked with the set naming
style. (default: None)
--inlinevar-naming-style <style>
Naming style matching correct inline iteration names.
(default: any)
--inlinevar-rgx <regexp>
Regular expression matching correct inline iteration
names. Overrides inlinevar-naming-style. If left
empty, inline iteration names will be checked with the
set naming style. (default: None)
--method-naming-style <style>
Naming style matching correct method names. (default:
snake_case)
--method-rgx <regexp>
Regular expression matching correct method names.
Overrides method-naming-style. If left empty, method
names will be checked with the set naming style.
(default: None)
--module-naming-style <style>
Naming style matching correct module names. (default:
snake_case)
--module-rgx <regexp>
Regular expression matching correct module names.
Overrides module-naming-style. If left empty, module
names will be checked with the set naming style.
(default: None)
--typevar-rgx <regexp>
Regular expression matching correct type variable
names. If left empty, type variable names will be
checked with the set naming style. (default: None)
--variable-naming-style <style>
Naming style matching correct variable names.
(default: snake_case)
--variable-rgx <regexp>
Regular expression matching correct variable names.
Overrides variable-naming-style. If left empty,
variable names will be checked with the set naming
style. (default: None)
--no-docstring-rgx <regexp>
Regular expression which should only match function or
class names that do not require a docstring. (default:
re.compile('^_'))
--docstring-min-length <int>
Minimum line length for functions/classes that require
docstrings, shorter ones are exempt. (default: -1)
Miscellaneous:
BaseChecker for encoding issues.
--notes <comma separated values>
List of note tags to take in consideration, separated
by a comma. (default: ('FIXME', 'XXX', 'TODO'))
--notes-rgx <regexp> Regular expression of note tags to take in
consideration. (default: )
Similarities:
Checks for similarities and duplicated code.
--min-similarity-lines <int>
Minimum lines number of a similarity. (default: 4)
--ignore-comments <y or n>
Comments are removed from the similarity computation
(default: True)
--ignore-docstrings <y or n>
Docstrings are removed from the similarity computation
(default: True)
--ignore-imports <y or n>
Imports are removed from the similarity computation
(default: True)
--ignore-signatures <y or n>
Signatures are removed from the similarity computation
(default: True)
Logging:
Checks use of the logging module.
--logging-modules <comma separated list>
Logging modules to check that the string format
arguments are in logging function parameter format.
(default: ('logging',))
--logging-format-style <old (%) or new ({)>
The type of string formatting that logging methods do.
`old` means using % formatting, `new` is for `{}`
formatting. (default: old)
Imports:
BaseChecker for import statements.
--deprecated-modules <modules>
Deprecated modules which should not be used, separated
by a comma. (default: ())
--preferred-modules <module:preferred-module>
Couples of modules and preferred modules, separated by
a comma. (default: ())
--import-graph <file.gv>
Output a graph (.gv or any supported image format) of
all (i.e. internal and external) dependencies to the
given file (report RP0402 must not be disabled).
(default: )
--ext-import-graph <file.gv>
Output a graph (.gv or any supported image format) of
external dependencies to the given file (report RP0402
must not be disabled). (default: )
--int-import-graph <file.gv>
Output a graph (.gv or any supported image format) of
internal dependencies to the given file (report RP0402
must not be disabled). (default: )
--known-standard-library <modules>
Force import order to recognize a module as part of
the standard compatibility libraries. (default: ())
--known-third-party <modules>
Force import order to recognize a module as part of a
third party library. (default: ('enchant',))
--allow-any-import-level <modules>
List of modules that can be imported at any level, not
just the top level one. (default: ())
--allow-wildcard-with-all <y or n>
Allow wildcard imports from modules that define
__all__. (default: False)
Installation on mega-linter Docker image
- PIP packages (Python):