Running Pylint

Invoking Pylint

Pylint is meant to be called from the command line. The usage is

pylint [options] module_or_package

You should give Pylint the name of a python package or module. Pylint will not import this package or module, though uses 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. The thing to keep in mind is that Pylint will try to convert the file name to a module name, and only be able to process the file if it succeeds.


should always work since the current working directory is automatically added on top of the python path

pylint directory/

will work if “directory” is a python package (i.e. has an file) or if “directory” is in the python path.

For more details on this see the Frequently Asked Questions.

You can also start a thin gui around Pylint (require tkinter) by typing


This should open a window where you can enter the name of the package or module to check, at Pylint messages will be displayed in the user interface.

It is also possible to call Pylint from an other python program, thanks to py_run() function in epylint module, assuming Pylint options are stored in pylint_options string, as:

from pylint import epylint as lint

To silently run Pylint on a module, and get its standard output and error:

from pylint import epylint as lint
(pylint_stdout, pylint_stderr) = lint.py_run('', return_std=True)

Command line options

First of all, we have two basic (but useful) options.

--version show program’s version number and exit
-h, --help show help about the command line options

Pylint is architectured around several checkers. By default all checkers are enabled. You can disable a specific checker or some of its messages or messages categories by specifying --disable=<id>. If you want to enable only some checkers or some message ids, first use --disable=all then --enable=<id> with <id> being a comma separated list of checker names and message identifiers. See the list of available features for a description of provided checkers with their functionalities. The --disable and --enable options can be used with comma separated lists mixing checkers, message ids and categories like -d C,W,E0611,design

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 --help

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:

  1. pylintrc in the current working directory
  2. .pylintrc in the current working directory
  3. If the current working directory is in a Python module, Pylint searches up the hierarchy of Python modules until it finds a pylintrc file. This allows you to specify coding standards on a module-by-module basis. Of course, a directory is judged to be a Python module if it contains an file.
  4. The file named by environment variable PYLINTRC
  5. if you have a home directory which isn’t /root:
    1. .pylintrc in your home directory
    2. .config/pylintrc in your home directory
  6. /etc/pylintrc

The --generate-rcfile option will generate a commented configuration file on standard output according to the current configuration and exit. This includes:

  • Any configuration file found as explained above
  • Options appearing before --generate-rcfile on the Pylint command line

Of course you can also start with the default values and hand tune the configuration.

Other useful global options include:

 Add <file> (may be a directory) to the black list. It should be a base name, not a path. Multiple entries can be given, separated by comma.
 Pickle collected data for later comparisons.
 Select output format (text, html, custom).
 Modifiy text output message template.
--list-msgs Generate pylint’s messages.
 Generate pylint’s full documentation, in reST format.

Parallel execution

It is possible to speed up the execution of Pylint. If the running computer has more CPUs than one, then the files to be checked could be spread on all processors to Pylint sub-processes. This functionality is exposed via -j command line parameter. It takes a number of sub-processes that should be spawned. If the provided number is 0 then the number of CPUs will be used. The default number of workers is 1.


pylint -j 4

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 completing checking a module.

There are some limitations in running checks in parallel in current implementation. It is not possible to use custom plugins (i.e. --load-plugins option), nor it is not possible to use initialization hooks (i.e. --init-hook option).

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