CheatPylint Python linter
Light · Postcard
102 × 152 mm · PDF
Dark · Postcard
102 × 152 mm · PDF
Ink saver · Postcard
102 × 152 mm · PDF
Light · A4 landscape
297 × 210 mm · PDF
Dark · A4 landscape
297 × 210 mm · PDF
Ink saver · A4 landscape
297 × 210 mm · PDF
Light · A3 landscape
420 × 297 mm · PDF
Dark · A3 landscape
420 × 297 mm · PDF
Ink saver · A3 landscape
420 × 297 mm · PDF
Start here
pylint <file.py>
Lint one file
pylint <package>
Lint a package
pylint --recursive=y .
Lint a whole tree
pylint -E <path>
Errors only, fast
pylint --disable=<msg>
Silence a message
pylint --generate-toml-config
Print a config file
pylint --fail-under=9 <path>
Gate CI on score
pylint --help-msg=<msg>
Explain a message
Concepts
- Config pyproject / pylintrc
- Targets files, packages
- Checkers enabled messages
- Output text, json2, score + exit code
Running
pylint <file.py>
Lint a single file
pylint <package>
Lint a package or module by name
A directory is only linted if it is a package (has
__init__.py) or you pass --recursive=y.
pylint --recursive=y <dir>
Lint every .py file under a directory
pylint -j 0 <path>
Use all CPU cores
Duplicate-code detection is incomplete when linting in
parallel.
pylint --ignore-paths=<regex>
Skip paths matching a regex
pylint --load-plugins=<module>
Load a plugin module
Choosing messages
pylint -E <path>
Report errors only (--errors-only)
pylint --disable=<msg>[,<msg>]
Turn messages off by id or symbol
pylint --enable=<msg>
Turn a message back on
pylint --disable=all --enable=<msg>
Run only the listed messages
pylint --disable=C,R <path>
Disable whole categories (C, R, W, E, F)
Output and score
pylint --fail-under=<score> <path>
Exit non-zero if the score is below it
pylint --score=n <path>
Hide the 0-10 score (--score=n)
pylint -f json2 <path>
Machine-readable JSON output
pylint --msg-template='<tmpl>'
Custom line, e.g. '{path}:{line}: {msg_id} {msg}'
pylint --exit-zero <path>
Always exit 0, even with findings
Help and discovery
pylint --help-msg=<msg>
Explain a message by id or symbol
pylint --list-msgs
List all messages by checker
pylint --list-msgs-enabled
Show which messages are on and off
Configuration
pylint --rcfile=<file> <path>
Use a specific config file
pylint --generate-toml-config
Print a documented pyproject-style config
pylint --generate-rcfile
Print a documented .pylintrc
Both generators include the effect of the other options you
pass, so pylint --disable=C0114 --generate-rcfile bakes it in.
pyproject.toml: [tool.pylint.main]
Project-wide settings (jobs, ignore-paths)
[tool.pylint."messages control"]
disable / enable lists in pyproject.toml
[tool.pylint.format] max-line-length = <n>
Change the line length limit (default 100)
[tool.pylint.basic] good-names = [<names>]
Allow short names like i, df, x
Inline control
# pylint: disable=<msg>
End of a line: silence it for that line
# pylint: disable=<msg>
On its own line: silence to end of the block
At module level, from there to the end of the file.
# pylint: disable-next=<msg>
Silence the following line only
pylint --enable=useless-suppression
Find pragmas that no longer silence anything
Messages you will meet
C0114 / C0115 / C0116
Missing module / class / function docstring
C0103 invalid-name
Name breaks the naming style
C0301 line-too-long
Line exceeds max-line-length
W0611 unused-import
Imported but never used
W0612 / W0613Unused variable / unused argument
E0401 import-error
Module cannot be imported (wrong env?)
E1101 no-memberAttribute not found on inferred type
E0602 undefined-variable
Name is not defined
W0102 dangerous-default-value
Mutable default argument
W0718 broad-exception-caught
except Exception is too general
W1203 logging-fstring-interpolation
Use lazy %s formatting in logging calls
R1705 no-else-return
else after return is unnecessary
R0913 too-many-arguments
More arguments than max-args (default 5)
R0902 / R0912 / R0914 / R0915
Too many attributes / branches / locals / statements
Recipes
# fail the job below 9.0, no score noise in logspylint --recursive=y --fail-under=9 src tests# 1. only real errors firstpylint -E --recursive=y .# 2. then one message at a timepylint --disable=all --enable=unused-import --recursive=y .[tool.pylint.main]jobs = 0ignore-paths = ["^migrations/"][tool.pylint."messages control"]disable = ["missing-docstring", "too-few-public-methods"][tool.pylint.format]max-line-length = 88pylint -f json2 --output=pylint.json src# or a compact gcc-style linepylint --msg-template='{path}:{line}: [{msg_id}] {msg}' -sn src
