On module packages or directories#
Pylint is meant to be called from the command line. The usage is
pylint [options] modules_or_packages
By default the
pylint command only accepts a list of python modules and packages.
On versions below 2.15, specifying a directory that is not an explicit package
__init__.py) results in an error:
pylint mydir ************* Module mydir mydir/__init__.py:1:0: F0010: error while code parsing: Unable to load file mydir/__init__.py: [Errno 2] No such file or directory: 'mydir/__init__.py' (parse-error)
Thus, on versions before 2.15, or when dealing with certain edge cases that have not yet been solved,
--recursive=y option allows for linting a namespace package:
pylint --recursive=y mydir mymodule mypackage
This option makes
pylint attempt to discover all modules (files ending with
and all explicit packages (all directories containing a
Pylint will not import this package or module, but it does use Python internals
to locate them and as such is subject to the same rules and configuration.
You should pay attention to your
PYTHONPATH, since it is a common error
to analyze an installed version of a module instead of the development version.
It is also possible to analyze Python files, with a few restrictions. As a convenience, you can give it a file name if it's possible to guess a module name from the file's path using the python path. Some examples:
pylint mymodule.py should always work since the current working
directory is automatically added on top of the python path
pylint directory/mymodule.py will work if:
directory is a python
package (i.e. has an
__init__.py file), an implicit namespace package
directory is in the python path.
With implicit namespace packages#
If the analyzed sources use implicit namespace packages (PEP 420), the source root(s) should
be specified using the
--source-roots option. Otherwise, the package names are
detected incorrectly, since implicit namespace packages don't contain an
It is also possible to specify both directories and files using globbing patterns:
pylint [options] packages/*/src
Command line options#
First of all, we have two basic (but useful) options.
show program's version number and exit
- -h, --help
show help about the command line options
Pylint is architected around several checkers. You can disable a specific
checker or some of its messages or message categories by specifying
--disable=<symbol>. If you want to enable only some checkers or some
message symbols, first use
<symbol> being a comma-separated list of checker
names and message symbols. See the list of available features for a
description of provided checkers with their functionalities.
--enable options can be used with comma-separated lists
mixing checkers, message ids and categories like
It is possible to disable all messages with
--disable=all. This is
useful to enable only a few checkers or a few messages by first
disabling everything, and then re-enabling only what you need.
Each checker has some specific options, which can take either a yes/no
value, an integer, a python regular expression, or a comma-separated
list of values (which are generally used to override a regular
expression in special cases). For a full list of options, use
Specifying all the options suitable for your setup and coding
standards can be tedious, so it is possible to use a configuration file to
specify the default values. You can specify a configuration file on the
command line using the
--rcfile option. Otherwise, Pylint searches for a
configuration file in the following order and uses the first one it finds:
pylintrcin the current working directory
.pylintrcin the current working directory
pyproject.tomlin the current working directory, providing it has at least one
pyproject.tomlmust prepend section names with
tool.pylint., for example
[tool.pylint.'MESSAGES CONTROL']. They can also be passed in on the command line.
setup.cfgin the current working directory, providing it has at least one
tox.iniin the current working directory, providing it has at least one
Pylint will search for the
pyproject.tomlfile up the directories hierarchy unless it's found, or a
.hgdirectory is found, or the file system root is approached.
If the current working directory is in a Python package, Pylint searches up the hierarchy of Python packages until it finds a
pylintrcfile. This allows you to specify coding standards on a module-by-module basis. Of course, a directory is judged to be a Python package if it contains an
The file named by environment variable
if you have a home directory which isn't
.pylintrcin your home directory
.config/pylintrcin your home directory
--generate-toml-config option will generate a commented configuration file
on standard output according to the current configuration and exit. This
Any configuration file found as explained above
Options appearing before
--generate-toml-configon the Pylint command line
Of course you can also start with the default values and hand-tune the configuration.
Other useful global options include:
Files or directories to be skipped. They should be base names, not paths.
Select output format (text, json, custom).
Modify text output message template.
Generate pylint's messages.
Display a list of what messages are enabled and disabled with the given configuration.
Generate pylint's full documentation, in reST format.
It is possible to speed up the execution of Pylint. If the running computer
has more CPUs than one, then the work for checking all files could be spread across all
cores via Pylints's sub-processes.
This functionality is exposed via the
-j command-line parameter.
If the provided number is 0, then the total number of CPUs will be autodetected and used.
pylint -j 4 mymodule1.py mymodule2.py mymodule3.py mymodule4.py
This will spawn 4 parallel Pylint sub-process, where each provided module will be checked in parallel. Discovered problems by checkers are not displayed immediately. They are shown just after checking a module is complete.
There is one known limitation with running checks in parallel as currently
implemented. Since the division of files into worker processes is indeterminate,
checkers that depend on comparing multiple files (e.g.
duplicate-code) can produce indeterminate results.
Pylint returns bit-encoded exit codes.
fatal message issued
error message issued
warning message issued
refactor message issued
convention message issued
For example, an exit code of
20 means there was at least one warning message (4)
and at least one convention message (16) and nothing else.