1pylint(1) General Commands Manual pylint(1)
2
6 pylint - python code static checker
7
10 pylint [ OPTIONS ] [ <arguments> ]
11
14 pylint is a Python source code analyzer which looks for programming
15 errors, helps enforcing a coding standard and sniffs for some code
16 smells (as defined in Martin Fowler's Refactoring book)
17 Pylint can be seen as another PyChecker since nearly all tests you can
19 do with PyChecker can also be done with Pylint. However, Pylint offers
20 some more features, like checking length of lines of code, checking if
21 variable names are well-formed according to your coding standard, or
22 checking if declared interfaces are truly implemented, and much more.
23 Additionally, it is possible to write plugins to add your own checks.
25 Pylint is shipped with "pyreverse" (UML diagram generator) and "symi‐
27 lar" (an independent similarities checker).
28
31 --version
32 show program's version number and exit
33 --help, -h
35 show this help message and exit
36 --long-help
38 more verbose help.
39
42 --rcfile=<file>
43 Specify a configuration file.
44 --init-hook=<code>
46 Python code to execute, usually for sys.path manipulation such
47 as pygtk.require().
48 --errors-only, -E
50 In error mode, checkers without error messages are disabled and
51 for others, only the ERROR messages are displayed, and no
52 reports are done by default
53 --py3k In Python 3 porting mode, all checkers will be disabled and only
55 messages emitted by the porting checker will be displayed
56 --verbose, -v
58 In verbose mode, extra non-checker-related info will be dis‐
59 played
60 --ignore=<file>[,<file>...]
62 Add files or directories to the blacklist. They should be base
63 names, not paths. [default: CVS]
64 --ignore-patterns=<pattern>[,<pattern>...]
66 Add files or directories matching the regex patterns to the
67 blacklist. The regex matches against base names, not paths.
68 [default: none]
69 --persistent=<y_or_n>
71 Pickle collected data for later comparisons. [default: yes]
72 --load-plugins=<modules>
74 List of plugins (as comma separated values of python modules
75 names) to load, usually to register additional checkers.
76 [default: none]
77 --jobs=<n-processes>, -j <n-processes>
79 Use multiple processes to speed up Pylint. Specifying 0 will
80 auto-detect the number of processors available to use. [default:
81 1]
82 --extension-pkg-whitelist=<pkg[,pkg]>
84 A comma-separated list of package or module names from where C
85 extensions may be loaded. Extensions are loading into the active
86 Python interpreter and may run arbitrary code [default: none]
87 --suggestion-mode=<yn>
89 When enabled, pylint would attempt to guess common misconfigura‐
90 tion and emit user-friendly hints instead of false-positive
91 error messages [default: yes]
92 --exit-zero
94 Always return a 0 (non-error) status code, even if lint errors
95 are found. This is primarily useful in continuous integration
96 scripts.
97
100 --help-msg=<msg-id>
101 Display a help message for the given message id and exit. The
102 value may be a comma separated list of message ids.
103 --list-msgs
105 Generate pylint's messages.
106 --list-conf-levels
108 Generate pylint's confidence levels.
109 --full-documentation
111 Generate pylint's full documentation.
112 --generate-rcfile
114 Generate a sample configuration file according to the current
115 configuration. You can put other options before this one to get
116 them in the generated configuration.
117
120 --confidence=<levels>
121 Only show warnings with the listed confidence levels. Leave
122 empty to show all. Valid levels: HIGH, INFERENCE, INFER‐
123 ENCE_FAILURE, UNDEFINED [default: none]
124 --enable=<msg ids>, -e <msg ids>
126 Enable the message, report, category or checker with the given
127 id(s). You can either give multiple identifier separated by
128 comma (,) or put this option multiple time (only on the command
129 line, not in the configuration file where it should appear only
130 once). See also the "--disable" option for examples.
131 --disable=<msg ids>, -d <msg ids>
133 Disable the message, report, category or checker with the given
134 id(s). You can either give multiple identifiers separated by
135 comma (,) or put this option multiple times (only on the command
136 line, not in the configuration file where it should appear only
137 once).You can also use "--disable=all" to disable everything
138 first and then reenable specific checks. For example, if you
139 want to run only the similarities checker, you can use "--dis‐
140 able=all --enable=similarities". If you want to run only the
141 classes checker, but have no Warning level messages displayed,
142 use"--disable=all --enable=classes --disable=W"
143
146 --output-format=<format>, -f <format>
147 Set the output format. Available formats are text, parseable,
148 colorized, json and msvs (visual studio). You can also give a
149 reporter class, e.g. mypackage.mymodule.MyReporterClass.
150 [default: text]
151 --reports=<y_or_n>, -r <y_or_n>
153 Tells whether to display a full report or only the messages
154 [default: no]
155 --evaluation=<python_expression>
157 Python expression which should return a note less than 10 (10 is
158 the highest note). You have access to the variables errors warn‐
159 ing, statement which respectively contain the number of errors /
160 warnings messages and the total number of statements analyzed.
161 This is used by the global evaluation report (RP0004). [default:
162 10.0 - ((float(5 * error + warning + refactor + convention) /
163 statement) * 10)]
164 --score=<y_or_n>, -s <y_or_n>
166 Activate the evaluation score. [default: yes]
167 --msg-template=<template>
169 Template used to display messages. This is a python new-style
170 format string used to format the message information. See doc
171 for all details
172
175 --good-names=<names>
176 Good variable names which should always be accepted, separated
177 by a comma [default: i,j,k,ex,Run,_]
178 --bad-names=<names>
180 Bad variable names which should always be refused, separated by
181 a comma [default: foo,bar,baz,toto,tutu,tata]
182 --name-group=<name1:name2>
184 Colon-delimited sets of names that determine each other's naming
185 style when the name regexes allow several styles. [default:
186 none]
187 --include-naming-hint=<y_or_n>
189 Include a hint for the correct naming format with invalid-name
190 [default: no]
191 --property-classes=<decorator names>
193 List of decorators that produce properties, such as
194 abc.abstractproperty. Add to this list to register other decora‐
195 tors that produce valid properties. [default: abc.abstractprop‐
196 erty]
197 --argument-naming-style=<style>
199 Naming style matching correct argument names [default:
200 snake_case]
201 --argument-rgx=<regexp>
203 Regular expression matching correct argument names. Overrides
204 argument-naming-style
205 --attr-naming-style=<style>
207 Naming style matching correct attribute names [default:
208 snake_case]
209 --attr-rgx=<regexp>
211 Regular expression matching correct attribute names. Overrides
212 attr-naming-style
213 --class-naming-style=<style>
215 Naming style matching correct class names [default: PascalCase]
216 --class-rgx=<regexp>
218 Regular expression matching correct class names. Overrides
219 class-naming-style
220 --class-attribute-naming-style=<style>
222 Naming style matching correct class attribute names [default:
223 any]
224 --class-attribute-rgx=<regexp>
226 Regular expression matching correct class attribute names. Over‐
227 rides class-attribute-naming-style
228 --const-naming-style=<style>
230 Naming style matching correct constant names [default:
231 UPPER_CASE]
232 --const-rgx=<regexp>
234 Regular expression matching correct constant names. Overrides
235 const-naming-style
236 --function-naming-style=<style>
238 Naming style matching correct function names [default:
239 snake_case]
240 --function-rgx=<regexp>
242 Regular expression matching correct function names. Overrides
243 function-naming-style
244 --inlinevar-naming-style=<style>
246 Naming style matching correct inline iteration names [default:
247 any]
248 --inlinevar-rgx=<regexp>
250 Regular expression matching correct inline iteration names.
251 Overrides inlinevar-naming-style
252 --method-naming-style=<style>
254 Naming style matching correct method names [default: snake_case]
255 --method-rgx=<regexp>
257 Regular expression matching correct method names. Overrides
258 method-naming-style
259 --module-naming-style=<style>
261 Naming style matching correct module names [default: snake_case]
262 --module-rgx=<regexp>
264 Regular expression matching correct module names. Overrides mod‐
265 ule-naming-style
266 --variable-naming-style=<style>
268 Naming style matching correct variable names [default:
269 snake_case]
270 --variable-rgx=<regexp>
272 Regular expression matching correct variable names. Overrides
273 variable-naming-style
274 --no-docstring-rgx=<regexp>
276 Regular expression which should only match function or class
277 names that do not require a docstring. [default: ^_]
278 --docstring-min-length=<int>
280 Minimum line length for functions/classes that require doc‐
281 strings, shorter ones are exempt. [default: -1]
282
285 --defining-attr-methods=<method names>
286 List of method names used to declare (i.e. assign) instance
287 attributes. [default: __init__,__new__,setUp]
288 --valid-classmethod-first-arg=<argument names>
290 List of valid names for the first argument in a class method.
291 [default: cls]
292 --valid-metaclass-classmethod-first-arg=<argument names>
294 List of valid names for the first argument in a metaclass class
295 method. [default: cls]
296 --exclude-protected=<protected access exclusions>
298 List of member names, which should be excluded from the pro‐
299 tected access warning. [default:
300 _asdict,_fields,_replace,_source,_make]
301
304 --max-args=<int>
305 Maximum number of arguments for function / method [default: 5]
306 --max-locals=<int>
308 Maximum number of locals for function / method body [default:
309 15]
310 --max-returns=<int>
312 Maximum number of return / yield for function / method body
313 [default: 6]
314 --max-branches=<int>
316 Maximum number of branch for function / method body [default:
317 12]
318 --max-statements=<int>
320 Maximum number of statements in function / method body [default:
321 50]
322 --max-parents=<num>
324 Maximum number of parents for a class (see R0901). [default: 7]
325 --max-attributes=<num>
327 Maximum number of attributes for a class (see R0902). [default:
328 7]
329 --min-public-methods=<num>
331 Minimum number of public methods for a class (see R0903).
332 [default: 2]
333 --max-public-methods=<num>
335 Maximum number of public methods for a class (see R0904).
336 [default: 20]
337 --max-bool-expr=<num>
339 Maximum number of boolean expressions in an if statement
340 [default: 5]
341
344 --overgeneral-exceptions=<comma-separated class names>
345 Exceptions that will emit a warning when being caught. Defaults
346 to "Exception" [default: Exception]
347
350 --max-line-length=<int>
351 Maximum number of characters on a single line. [default: 100]
352 --ignore-long-lines=<regexp>
354 Regexp for a line that is allowed to be longer than the limit.
355 [default: ^\s*(# )?<?https?://\S+>?$]
356 --single-line-if-stmt=<y_or_n>
358 Allow the body of an if to be on the same line as the test if
359 there is no else. [default: no]
360 --single-line-class-stmt=<y_or_n>
362 Allow the body of a class to be on the same line as the declara‐
363 tion if body contains single statement. [default: no]
364 --no-space-check=trailing-comma,dict-separator,empty-line
366 List of optional constructs for which whitespace checking is
367 disabled. `dict-separator` is used to allow tabulation in dicts,
368 etc.: {1 : 1,\n222: 2}. `trailing-comma` allows a space between
369 comma and closing bracket: (a, ). `empty-line` allows space-only
370 lines. [default: trailing-comma,dict-separator]
371 --max-module-lines=<int>
373 Maximum number of lines in a module [default: 1000]
374 --indent-string=<string>
376 String used as indentation unit. This is usually " " (4 spa‐
377 ces) or "\t" (1 tab). [default: ' ']
378 --indent-after-paren=<int>
380 Number of spaces of indent required inside a hanging or contin‐
381 ued line. [default: 4]
382 --expected-line-ending-format=<empty or LF or CRLF>
384 Expected format of line ending, e.g. empty (any line ending), LF
385 or CRLF. [default: none]
386
389 --deprecated-modules=<modules>
390 Deprecated modules which should not be used, separated by a
391 comma [default: optparse,tkinter.tix]
392 --import-graph=<file.dot>
394 Create a graph of every (i.e. internal and external) dependen‐
395 cies in the given file (report RP0402 must not be disabled)
396 [default: none]
397 --ext-import-graph=<file.dot>
399 Create a graph of external dependencies in the given file
400 (report RP0402 must not be disabled) [default: none]
401 --int-import-graph=<file.dot>
403 Create a graph of internal dependencies in the given file
404 (report RP0402 must not be disabled) [default: none]
405 --known-standard-library=<modules>
407 Force import order to recognize a module as part of the standard
408 compatibility libraries. [default: none]
409 --known-third-party=<modules>
411 Force import order to recognize a module as part of a third
412 party library. [default: enchant]
413 --analyse-fallback-blocks=<y_or_n>
415 Analyse import fallback blocks. This can be used to support both
416 Python 2 and 3 compatible code, which means that the block might
417 have code that exists only in one or another interpreter, lead‐
418 ing to false positives when analysed. [default: no]
419 --allow-wildcard-with-all=<y_or_n>
421 Allow wildcard imports from modules that define __all__.
422 [default: no]
423
426 --logging-modules=<comma separated list>
427 Logging modules to check that the string format arguments are in
428 logging function parameter format [default: logging]
429
432 --notes=<comma separated values>
433 List of note tags to take in consideration, separated by a
434 comma. [default: FIXME,XXX,TODO]
435
438 --max-nested-blocks=<int>
439 Maximum number of nested blocks for function / method body
440 [default: 5]
441 --never-returning-functions=NEVER_RETURNING_FUNCTIONS
443 Complete name of functions that never returns. When checking for
444 inconsistent-return-statements if a never returning function is
445 called then it will be considered as an explicit return state‐
446 ment and no message will be printed. [default: sys.exit]
447
450 --min-similarity-lines=<int>
451 Minimum lines number of a similarity. [default: 4]
452 --ignore-comments=<y or n>
454 Ignore comments when computing similarities. [default: yes]
455 --ignore-docstrings=<y or n>
457 Ignore docstrings when computing similarities. [default: yes]
458 --ignore-imports=<y or n>
460 Ignore imports when computing similarities. [default: no]
461
464 --spelling-dict=<dict name>
465 Spelling dictionary name. Available dictionaries: none. To make
466 it working install python-enchant package. [default: none]
467 --spelling-ignore-words=<comma separated words>
469 List of comma separated words that should not be checked.
470 [default: none]
471 --spelling-private-dict-file=<path to file>
473 A path to a file that contains private dictionary; one word per
474 line. [default: none]
475 --spelling-store-unknown-words=<y_or_n>
477 Tells whether to store unknown words to indicated private dic‐
478 tionary in --spelling-private-dict-file option instead of rais‐
479 ing a message. [default: no]
480 --max-spelling-suggestions=N
482 Limits count of emitted suggestions for spelling mistakes
483 [default: 4]
484
487 --ignore-on-opaque-inference=<y_or_n>
488 This flag controls whether pylint should warn about no-member
489 and similar checks whenever an opaque object is returned when
490 inferring. The inference can return multiple potential results
491 while evaluating a Python object, but some branches might not be
492 evaluated, which results in partial inference. In that case, it
493 might be useful to still emit no-member and other checks for the
494 rest of the inferred objects. [default: yes]
495 --ignore-mixin-members=<y_or_n>
497 Tells whether missing members accessed in mixin class should be
498 ignored. A mixin class is detected if its name ends with "mixin"
499 (case insensitive). [default: yes]
500 --ignore-none=<y_or_n>
502 Tells whether to warn about missing members when the owner of
503 the attribute is inferred to be None [default: yes]
504 --ignored-modules=<module names>
506 List of module names for which member attributes should not be
507 checked (useful for modules/projects where namespaces are manip‐
508 ulated during runtime and thus existing member attributes cannot
509 be deduced by static analysis. It supports qualified module
510 names, as well as Unix pattern matching. [default: none]
511 --ignored-classes=<members names>
513 List of class names for which member attributes should not be
514 checked (useful for classes with dynamically set attributes).
515 This supports the use of qualified names. [default: opt‐
516 parse.Values,thread._local,_thread._local]
517 --generated-members=<members names>
519 List of members which are set dynamically and missed by pylint
520 inference system, and so shouldn't trigger E1101 when accessed.
521 Python regular expressions are accepted. [default: none]
522 --contextmanager-decorators=<decorator names>
524 List of decorators that produce context managers, such as con‐
525 textlib.contextmanager. Add to this list to register other deco‐
526 rators that produce valid context managers. [default: con‐
527 textlib.contextmanager]
528 --missing-member-hint-distance=<member hint edit distance>
530 The minimum edit distance a name should have in order to be con‐
531 sidered a similar match for a missing member name. [default: 1]
532 --missing-member-max-choices=<member hint max choices>
534 The total number of similar names that should be taken in con‐
535 sideration when showing a hint for a missing member. [default:
536 1]
537 --missing-member-hint=<missing member hint>
539 Show a hint with possible names when a member name was not
540 found. The aspect of finding the hint is based on edit distance.
541 [default: yes]
542
545 --init-import=<y_or_n>
546 Tells whether we should check for unused import in __init__
547 files. [default: no]
548 --dummy-variables-rgx=<regexp>
550 A regular expression matching the name of dummy variables (i.e.
551 expectedly not used). [default: _+$|(_[a-zA-Z0-9_]*[a-zA-
552 Z0-9]+?$)|dummy|^ignored_|^unused_]
553 --additional-builtins=<comma separated list>
555 List of additional names supposed to be defined in builtins.
556 Remember that you should avoid to define new builtins when pos‐
557 sible. [default: none]
558 --callbacks=<callbacks>
560 List of strings which can identify a callback function by name.
561 A callback name must start or end with one of those strings.
562 [default: cb_,_cb]
563 --redefining-builtins-modules=<comma separated list>
565 List of qualified module names which can have objects that can
566 redefine builtins. [default:
567 six.moves,past.builtins,future.builtins,builtins,io]
568 --ignored-argument-names=<regexp>
570 Argument names that match this expression will be ignored.
571 Default to name with leading underscore [default:
572 _.*|^ignored_|^unused_]
573 --allow-global-unused-variables=<y_or_n>
575 Tells whether unused global variables should be treated as a
576 violation. [default: yes]
577
580 The following environment variables are used:
581 * PYLINTHOME
582 Path to the directory where persistent data for the run will be
583 stored. If not found, it defaults to ~/.pylint.d/ or .pylint.d (in the
584 current working directory).
585 * PYLINTRC
586 Path to the configuration file. See the documentation for the
587 method used to search for configuration file.
588
591 Using the default text output, the message format is :
592 MESSAGE_TYPE: LINE_NUM:[OBJECT:] MESSAGE
594 There are 5 kind of message types :
596 * (C) convention, for programming standard violation
597 * (R) refactor, for bad code smell
598 * (W) warning, for python specific problems
599 * (E) error, for probable bugs in the code
600 * (F) fatal, if an error occurred which prevented pylint from doing
601 further processing.
602
605 Pylint should leave with following status code:
606 * 0 if everything went fine
607 * 1 if a fatal message was issued
608 * 2 if an error message was issued
609 * 4 if a warning message was issued
610 * 8 if a refactor message was issued
611 * 16 if a convention message was issued
612 * 32 on usage error
613 status 1 to 16 will be bit-ORed so you can know which different cate‐
615 gories has been issued by analysing pylint output status code
616
619 /usr/share/doc/pythonX.Y-pylint/
620
623 Please report bugs on the project's mailing list: mailto:code-qual‐
624 ity@python.org
625
628 Python Code Quality Authority <code-quality@python.org>
629pylint 2018-06-13 pylint(1)