Your company here — click to reach over 10,000 unique daily visitors

pycodestyle - Man Page

Examples (TL;DR)


pycodestyle — pycodestyle documentation

Python style guide checker

pycodestyle (formerly pep8) is a tool to check your Python code against some of the style conventions in PEP 8.



pycodestyle is a tool to check your Python code against some of the style conventions in PEP 8.


  • Plugin architecture: Adding new checks is easy.
  • Parseable output: Jump to error location in your editor.
  • Small: Just one Python file, requires only stdlib.  You can use just the pycodestyle.py file for this purpose.
  • Comes with a comprehensive test suite.


This utility does not enforce every single rule of PEP 8.  It helps to verify that some coding conventions are applied but it does not intend to be exhaustive.  Some rules cannot be expressed with a simple algorithm, and other rules are only guidelines which you could circumvent when you need to.

Always remember this statement from PEP 8:

A style guide is about consistency. Consistency with this style guide is important. Consistency within a project is more important. Consistency within one module or function is most important.

Among other things, these features are currently not in the scope of the pycodestyle library:

  • naming conventions: this kind of feature is supported through plugins. Install flake8 and the pep8-naming extension to use this feature.
  • docstring conventions: they are not in the scope of this library; see the pydocstyle project.
  • automatic fixing: see the section PEP8 Fixers in the related tools page.


You can install, upgrade, uninstall pycodestyle.py with these commands:

$ pip install pycodestyle
$ pip install --upgrade pycodestyle
$ pip uninstall pycodestyle

Example usage and output

$ pycodestyle --first optparse.py
optparse.py:69:11: E401 multiple imports on one line
optparse.py:77:1: E302 expected 2 blank lines, found 1
optparse.py:88:5: E301 expected 1 blank line, found 0
optparse.py:347:31: E211 whitespace before '('
optparse.py:357:17: E201 whitespace after '{'
optparse.py:472:29: E221 multiple spaces before operator

You can also make pycodestyle.py show the source code for each error, and even the relevant text from PEP 8:

$ pycodestyle --show-source --show-pep8 testing/data/E40.py
testing/data/E40.py:2:10: E401 multiple imports on one line
import os, sys
    Imports should usually be on separate lines.

    Okay: import os\nimport sys
    E401: import sys, os

Or you can display how often each error was found:

$ pycodestyle --statistics -qq Python-2.5/Lib
232     E201 whitespace after '['
599     E202 whitespace before ')'
631     E203 whitespace before ','
842     E211 whitespace before '('
2531    E221 multiple spaces before operator
4473    E301 expected 1 blank line, found 0
4006    E302 expected 2 blank lines, found 1
165     E303 too many blank lines (4)
325     E401 multiple imports on one line
3615    E501 line too long (82 characters)

You can also make pycodestyle.py show the error text in different formats by using --format having options default/pylint/custom:

$ pycodestyle testing/data/E40.py --format=default
testing/data/E40.py:2:10: E401 multiple imports on one line

$ pycodestyle testing/data/E40.py --format=pylint
testing/data/E40.py:2: [E401] multiple imports on one line

$ pycodestyle testing/data/E40.py --format='%(path)s|%(row)d|%(col)d| %(code)s %(text)s'
testing/data/E40.py|2|10| E401 multiple imports on one line

Variables in the custom format option

pathFile name
rowRow number
colColumn number
codeError code
textError text

Quick help is available on the command line:

$ pycodestyle -h
Usage: pycodestyle [options] input ...

  --version            show program's version number and exit
  -h, --help           show this help message and exit
  -v, --verbose        print status messages, or debug with -vv
  -q, --quiet          report only file names, or nothing with -qq
  --first              show first occurrence of each error
  --exclude=patterns   exclude files or directories which match these comma
                       separated patterns (default: .svn,CVS,.bzr,.hg,.git)
  --filename=patterns  when parsing directories, only check filenames matching
                       these comma separated patterns (default: *.py)
  --select=errors      select errors and warnings (e.g. E,W6)
  --ignore=errors      skip errors and warnings (e.g. E4,W)
  --show-source        show source code for each error
  --show-pep8          show text of PEP 8 for each error (implies --first)
  --statistics         count errors and warnings
  --count              print total number of errors and warnings to standard
                       error and set exit code to 1 if total is not null
  --max-line-length=n  set maximum allowed line length (default: 79)
  --max-doc-length=n   set maximum allowed doc line length and perform these
                       checks (unchecked if not set)
  --indent-size=n      set how many spaces make up an indent (default: 4)
  --hang-closing       hang closing bracket instead of matching indentation of
                       opening bracket's line
  --format=format      set the error format [default|pylint|<custom>]
  --diff               report only lines changed according to the unified diff
                       received on STDIN

  Testing Options:
    --benchmark        measure processing speed

    The project options are read from the [pycodestyle] section of the
    tox.ini file or the setup.cfg file located in any parent folder of the
    path(s) being processed.  Allowed options are: exclude, filename,
    select, ignore, max-line-length, max-doc-length, hang-closing, count,
    format, quiet, show-pep8, show-source, statistics, verbose.

    --config=path      user config file location
    (default: ~/.config/pycodestyle)


The behaviour may be configured at two levels, the user and project levels.

At the user level, settings are read from the following locations:

If on Windows:


Otherwise, if the XDG_CONFIG_HOME environment variable is defined:


Else if XDG_CONFIG_HOME is not defined:



count = False
ignore = E226,E302,E71
max-line-length = 160
statistics = True

At the project level, a setup.cfg file or a tox.ini file is read if present. If none of these files have a [pycodestyle] section, no project specific configuration is loaded.

Error codes

This is the current list of error and warning codes:

codesample message
E101indentation contains mixed spaces and tabs
E111indentation is not a multiple of four
E112expected an indented block
E113unexpected indentation
E114indentation is not a multiple of four (comment)
E115expected an indented block (comment)
E116unexpected indentation (comment)
E121 (*^)continuation line under-indented for hanging indent
E122 (^)continuation line missing indentation or outdented
E123 (*)closing bracket does not match indentation of opening bracket's line
E124 (^)closing bracket does not match visual indentation
E125 (^)continuation line with same indent as next logical line
E126 (*^)continuation line over-indented for hanging indent
E127 (^)continuation line over-indented for visual indent
E128 (^)continuation line under-indented for visual indent
E129 (^)visually indented line with same indent as next logical line
E131 (^)continuation line unaligned for hanging indent
E133 (*)closing bracket is missing indentation
E201whitespace after '('
E202whitespace before ')'
E203whitespace before ',', ';', or ':'
E211whitespace before '('
E221multiple spaces before operator
E222multiple spaces after operator
E223tab before operator
E224tab after operator
E225missing whitespace around operator
E226 (*)missing whitespace around arithmetic operator
E227missing whitespace around bitwise or shift operator
E228missing whitespace around modulo operator
E231missing whitespace after ',', ';', or ':'
E241 (*)multiple spaces after ','
E242 (*)tab after ','
E251unexpected spaces around keyword / parameter equals
E261at least two spaces before inline comment
E262inline comment should start with '# '
E265block comment should start with '# '
E266too many leading '#' for block comment
E271multiple spaces after keyword
E272multiple spaces before keyword
E273tab after keyword
E274tab before keyword
E275missing whitespace after keyword
E3Blank line
E301expected 1 blank line, found 0
E302expected 2 blank lines, found 0
E303too many blank lines (3)
E304blank lines found after function decorator
E305expected 2 blank lines after end of function or class
E306expected 1 blank line before a nested definition
E401multiple imports on one line
E402module level import not at top of file
E5Line length
E501 (^)line too long (82 > 79 characters)
E502the backslash is redundant between brackets
E701multiple statements on one line (colon)
E702multiple statements on one line (semicolon)
E703statement ends with a semicolon
E704 (*)multiple statements on one line (def)
E711 (^)comparison to None should be 'if cond is None:'
E712 (^)comparison to True should be 'if cond is True:' or 'if cond:'
E713test for membership should be 'not in'
E714test for object identity should be 'is not'
E721 (^)do not compare types, use 'isinstance()'
E722do not use bare except, specify exception instead
E731do not assign a lambda expression, use a def
E741do not use variables named 'l', 'O', or 'I'
E742do not define classes named 'l', 'O', or 'I'
E743do not define functions named 'l', 'O', or 'I'
E901SyntaxError or IndentationError
W1Indentation warning
W191indentation contains tabs
W2Whitespace warning
W291trailing whitespace
W292no newline at end of file
W293blank line contains whitespace
W3Blank line warning
W391blank line at end of file
W5Line break warning
W503 (*)line break before binary operator
W504 (*)line break after binary operator
W505 (*^)doc line too long (82 > 79 characters)
W6Deprecation warning
W605invalid escape sequence 'x'

(*) In the default configuration, the checks E121, E123, E126, E133, E226, E241, E242, E704, W503, W504 and W505 are ignored because they are not rules unanimously accepted, and PEP 8 does not enforce them. Please note that if the option --ignore=errors is used, the default configuration will be overridden and ignore only the check(s) you skip. The check W503 is mutually exclusive with check W504. The check E133 is mutually exclusive with check E123.  Use switch --hang-closing to report E133 instead of E123. Use switch --max-doc-length=n to report W505.

(^) These checks can be disabled at the line level using the # noqa special comment.  This possibility should be reserved for special cases.

Special cases aren't special enough to break the rules.

Note: most errors can be listed with such one-liner:

$ python pycodestyle.py --first --select E,W testing/data --format '%(code)s: %(text)s'

Advanced Usage

Automated tests

You can also execute pycodestyle tests from Python code.  For example, this can be highly useful for automated testing of coding style conformance in your project:

import unittest
import pycodestyle

class TestCodeFormat(unittest.TestCase):

    def test_conformance(self):
        """Test that we conform to PEP-8."""
        style = pycodestyle.StyleGuide(quiet=True)
        result = style.check_files(['file1.py', 'file2.py'])
        self.assertEqual(result.total_errors, 0,
                         "Found code style errors (and warnings).")

There's also a shortcut for checking a single file:

import pycodestyle

fchecker = pycodestyle.Checker('testing/data/E27.py', show_source=True)
file_errors = fchecker.check_all()

print("Found %s errors (and warnings)" % file_errors)

Configuring tests

You can configure automated pycodestyle tests in a variety of ways.

For example, you can pass in a path to a configuration file that pycodestyle should use:

import pycodestyle

style = pycodestyle.StyleGuide(config_file='/path/to/tox.ini')

You can also set specific options explicitly:

style = pycodestyle.StyleGuide(ignore=['E501'])

Skip file header

Another example is related to the feature request #143: skip a number of lines at the beginning and the end of a file.  This use case is easy to implement through a custom wrapper for the PEP 8 library:

import pycodestyle

LINES_SLICE = slice(14, -20)

class StyleGuide(pycodestyle.StyleGuide):
    """This subclass of pycodestyle.StyleGuide will skip the first and last lines
    of each file."""

    def input_file(self, filename, lines=None, expected=None, line_offset=0):
        if lines is None:
            assert line_offset == 0
            line_offset = LINES_SLICE.start or 0
            lines = pycodestyle.readlines(filename)[LINES_SLICE]
        return super(StyleGuide, self).input_file(
            filename, lines=lines, expected=expected, line_offset=line_offset)

if __name__ == '__main__':
    style = StyleGuide(parse_argv=True, config_file=True)
    report = style.check_files()
    if report.total_errors:
        raise SystemExit(1)

This module declares a lines' window which skips 14 lines at the beginning and 20 lines at the end.  If there's no line to skip at the end, it could be changed with LINES_SLICE = slice(14, None) for example.

You can save it in a file and use it with the same options as the original pycodestyle.

Pycodestyle API

The library provides classes which are usable by third party tools.

Checker Classes

The StyleGuide class is used to configure a style guide checker instance to check multiple files.

The Checker class can be used to check a single file.

class pycodestyle.StyleGuide(parse_argv=False, config_file=None, parser=None, paths=None, report=None, **kwargs)

Initialize a PEP-8 instance with few options.


Initialize the report instance.


Run all checks on the paths.

input_file(filename, lines=None, expected=None, line_offset=0)

Run all checks on a Python source file.


Check all files in this directory and all subdirectories.

excluded(filename, parent=None)

Check if the file should be excluded.

Check if 'options.exclude' contains a pattern matching filename.


Check if the error code should be ignored.

If 'options.select' contains a prefix of the error code, return False.  Else, if 'options.ignore' contains a prefix of the error code, return True.


Get all the checks for this category.

Find all globally visible functions where the first argument name starts with argument_name and which contain selected tests.

class pycodestyle.Checker(filename=None, lines=None, report=None, **kwargs)

Load a Python source file, tokenize it, check coding style.


Get the next line from the input buffer.

run_check(check, argument_names)

Run a check plugin.


Run all physical checks on a raw input line.


Build a logical line from tokens.


Build a line from tokens and run all logical checks on it.


Build the file's AST and run all AST checks.


Tokenize file, run physical line checks and yield tokens.

check_all(expected=None, line_offset=0)

Run all checks on the input file.

Report Classes

class pycodestyle.BaseReport(options)

Collect the results of the checks.


Start the timer.


Stop the timer.

init_file(filename, lines, expected, line_offset)

Signal a new file.


Signal a new logical line.

error(line_number, offset, text, check)

Report an error, according to options.


Return the count of errors and warnings for this file.


Return the total count of errors and warnings.


Get statistics for message codes that start with the prefix.

prefix='' matches all errors and warnings prefix='E' matches all errors prefix='W' matches all warnings prefix='E4' matches all errors that have to do with imports


Print overall statistics (number of errors and warnings).


Print benchmark numbers.

class pycodestyle.FileReport(options)

Collect the results of the checks and print the filenames.

class pycodestyle.StandardReport(options)

Collect and print the results of the checks.

class pycodestyle.DiffReport(options)

Collect and print the results for the changed lines only.



Return the amount of indentation.

Tabs are expanded to the next multiple of 8.


Replace contents with 'xxx' to prevent syntax matching.

pycodestyle.read_config(options, args, arglist, parser)

Read and parse configurations.

If a config file is specified on the command line with the "--config" option, then only it is used for configuration.

Otherwise, the user configuration (~/.config/pycodestyle) and any local configurations in the current directory or above will be merged together (in that order) using the read method of ConfigParser.

pycodestyle.process_options(arglist=None, parse_argv=False, config_file=None)

Process options passed either via arglist or command line args.

Passing in the config_file parameter allows other tools, such as flake8 to specify their own options to be processed in pycodestyle.

pycodestyle.register_check(func_or_cls, codes=None)

Register a new check object.

Developer's Notes

Source code

The source code is currently available on GitHub under the terms and conditions of the Expat license.  Fork away!

  • Source code and issue tracker on GitHub.
  • Continuous tests against Python 2.7 and 3.5+ as well as the nightly Python build and PyPy, on GitHub Actions.


Some high-level aims and directions to bear in mind for contributions:

  • pycodestyle is intended to be as fast as possible. Using the ast module defeats that purpose. The pep8-naming plugin exists for this sort of functionality.
  • If you want to provide extensibility / plugins, please see flake8 - pycodestyle doesn't want or need a plugin architecture.
  • pycodestyle aims to have no external dependencies.


You can add checks to this program by writing plugins.  Each plugin is a simple function that is called for each line of source code, either physical or logical.

Physical line:

  • Raw line of text from the input file.

Logical line:

  • Multi-line statements converted to a single line.
  • Stripped left and right.
  • Contents of strings replaced with "xxx" of same length.
  • Comments removed.

The check function requests physical or logical lines by the name of the first argument:

def maximum_line_length(physical_line)
def extraneous_whitespace(logical_line)
def blank_lines(logical_line, blank_lines, indent_level, line_number)

The last example above demonstrates how check plugins can request additional information with extra arguments.  All attributes of the Checker object are available.  Some examples:

  • lines: a list of the raw lines from the input file
  • tokens: the tokens that contribute to this logical line
  • line_number: line number in the input file
  • total_lines: number of lines in the input file
  • blank_lines: blank lines before this one
  • indent_char: indentation character in this file (" " or "\t")
  • indent_level: indentation (with tabs expanded to multiples of 8)
  • previous_indent_level: indentation on previous line
  • previous_logical: previous logical line

Check plugins can also maintain per-file state. If you need this, declare a parameter named checker_state. You will be passed a dict, which will be the same one for all lines in the same file but a different one for different files. Each check plugin gets its own dict, so you don't need to worry about clobbering the state of other plugins.

The docstring of each check function shall be the relevant part of text from PEP 8.  It is printed if the user enables --show-pep8. Several docstrings contain examples directly from the PEP 8 document.

Okay: spam(ham[1], {eggs: 2})
E201: spam( ham[1], {eggs: 2})

These examples are verified automatically by test_self_doctest.py. You can add examples for your own check functions. The format is simple: "Okay" or error/warning code followed by colon and space, the rest of the line is example source code.  If you put 'r' before the docstring, you can use \n for newline and \t for tab.

Then be sure to pass the tests:

$ pytest tests
$ python pycodestyle.py --verbose pycodestyle.py

When contributing to pycodestyle, please observe our Code of Conduct.

To run the tests, the core developer team and GitHub Actions use tox:

$ pip install -r dev-requirements.txt
$ tox

All the tests should pass for all available interpreters, with the summary of:

congratulations :)


2.11.1 (2023-10-12)


  • E275: fix false positive with fstrings containing keyword parts in python 3.12

2.11.0 (2023-07-29)


  • Drop EOL python 3.6 / 3.7.  PR #1129, #1160.
  • Add support for python 3.12.  PR #1147, #1148, #1152, #1153, #1154, #1163, #1164, #1165, #1166, #1176, #1177, #1182.
  • E721: adjust handling of type comparison.  Allowed forms are now isinstance(x, t) or type(x) is t.  PR #1086, #1167.
  • Remove handling of python 2 <> operator.  PR #1161.
  • W606: removed.  async / await are always keywords.  PR #1162.
  • Internal: move tests to pytest.  PR #1168, #1169, #1171, #1173, #1174, #1175.
  • Remove handling of python 2 ur'' strings.  PR #1181.

2.10.0 (2022-11-23)


  • E231: allow trailing comma inside 1-tuples in [].  PR #1108.
  • W601, W602, W603, W604: removed (no longer relevant in python 3).  PR #1111.
  • E741: also apply to lambdas.  PR #1106.
  • E741: fix false positive for comparison operators.  PR #1118.

2.9.1 (2022-08-03)


  • E275: fix false positive for yield expressions.  PR #1091.

2.9.0 (2022-07-30)


  • E221, E222, E223, E224: add support for := operator.  PR #1032.
  • Drop python 2.7 / 3.5.
  • E262: consider non-breaking spaces (\xa0) as whitespace.  PR #1035.
  • Improve performance of _is_binary_operator.  PR #1052.
  • E275: requires whitespace around keywords.  PR #1063.
  • Add support for python 3.11. PR #1070.

2.8.0 (2021-10-10)


  • Drop python 3.4.  PR #982.
  • E712: fix false negative with multiple comparisons.  PR #987.
  • E211: fix false positives with match.  PR #989.
  • E772: improve performance of bare except check.  PR #992.
  • Backport tokenize performance improvement from python 3.10.  PR #993.
  • E225: fix for lambdas containing positional-only args.  PR #1012.
  • Remove indent_size_str "setting".  PR #995.
  • E402: allow __all__ to be typed.  PR #1019.
  • E225: fix false positives for * in case.  PR #1003.
  • E201: detect tabs as whitespace.  PR #1015.

2.7.0 (2021-03-14)


  • Fix physical checks (such as W191) at end of file.  PR #961.
  • Add --indent-size option (defaulting to 4).  PR #970.
  • W605: fix escaped crlf false positive on windows.  PR #976.

2.6.0 (2020-05-11)


  • Anthony Sottile (@asottile) joined the team as a core developer. :tada:


  • E306: fix detection inside async def.  PR #929.
  • E301: fix regression disallowing decorated one-liners.  PR #927.
  • E714: fix false positive with chained is not.  PR #931.

2.6.0a1 (2020-04-23)

New checks:

  • E225: require whitespace around and in is and or.  PR #847.


  • E117: fix indentation using tabs by treating as 8-space indents.  PR #837.
  • E721: fix false positive with names containg istype.  PR #850.
  • E741: allow l as a named argument in a function call.  PR #853.
  • E302: fix false-negative with decorated functions.  PR #859.
  • W504: ellipsis (...) is no longer treated as a binary operator.  PR #875.
  • E402: allow with, if, elif, else to guard imports.  PR #834.
  • Add support for assignment expressions := (PEP 572).  PR #879.
  • Add support for positional-only arguments / (PEP 570).  PR #872, #918.
  • Add support for python 3.8.
  • Add support for matrix multiplication operator @ (PEP 465).  PR #897.
  • Support visual indent for continuation lines for with / assert / raise.  PR #912.
  • E302: allow two blank lines after a block of one-liners.  PR #913.
  • E302: allow two-and-fewer newlines at the top of the file.  PR #919.

2.5.0 (2019-01-29)

New checks:

  • E117: Over-indented code blocks
  • W505: Maximum doc-string length only when configured with --max-doc-length


  • Remove support for EOL Python 2.6 and 3.3. PR #720.
  • Add E117 error for over-indented code blocks.
  • Allow W605 to be silenced by # noqa and fix the position reported by W605
  • Allow users to omit blank lines around one-liner definitions of classes and functions
  • Include the function return annotation (->) as requiring surrounding whitespace only on Python 3
  • Verify that only names can follow await. Previously we allowed numbers and strings.
  • Add support for Python 3.7
  • Fix detection of annotated argument defaults for E252
  • Correct the position reported by W504

2.4.0 (2018-04-10)

New checks:

  • Add W504 warning for checking that a break doesn't happen after a binary operator. This check is ignored by default. PR #502.
  • Add W605 warning for invalid escape sequences in string literals. PR #676.
  • Add W606 warning for 'async' and 'await' reserved keywords being introduced in Python 3.7. PR #684.
  • Add E252 error for missing whitespace around equal sign in type annotated function arguments with defaults values. PR #717.


  • An internal bisect search has replaced a linear search in order to improve efficiency. PR #648.
  • pycodestyle now uses PyPI trove classifiers in order to document supported python versions on PyPI. PR #654.
  • 'setup.cfg' '[wheel]' section has been renamed to '[bdist_wheel]', as the former is legacy. PR #653.
  • pycodestyle now handles very long lines much more efficiently for python 3.2+. Fixes #643. PR #644.
  • You can now write 'pycodestyle.StyleGuide(verbose=True)' instead of 'pycodestyle.StyleGuide(verbose=True, paths=['-v'])' in order to achieve verbosity. PR #663.
  • The distribution of pycodestyle now includes the license text in order to comply with open source licenses which require this. PR #694.
  • 'maximum_line_length' now ignores shebang ('#!') lines. PR #736.
  • Add configuration option for the allowed number of blank lines. It is implemented as a top level dictionary which can be easily overwritten. Fixes #732. PR #733.


  • Prevent a 'DeprecationWarning', and a 'SyntaxError' in future python, caused by an invalid escape sequence. PR #625.
  • Correctly report E501 when the first line of a docstring is too long. Resolves #622. PR #630.
  • Support variable annotation when variable start by a keyword, such as class variable type annotations in python 3.6. PR #640.
  • pycodestyle internals have been changed in order to allow 'python3 -m cProfile' to report correct metrics. PR #647.
  • Fix a spelling mistake in the description of E722. PR #697.
  • 'pycodestyle --diff' now does not break if your 'gitconfig' enables 'mnemonicprefix'. PR #706.

2.3.1 (2017-01-31)


  • Fix regression in detection of E302 and E306; #618, #620

2.3.0 (2017-01-30)

New Checks:

  • Add E722 warning for bare except clauses
  • Report E704 for async function definitions (async def)


  • Fix another E305 false positive for variables beginning with "class" or "def"
  • Fix detection of multiple spaces between async and def
  • Fix handling of variable annotations. Stop reporting E701 on Python 3.6 for variable annotations.

2.2.0 (2016-11-14)


  • Added Make target to obtain proper tarball file permissions; #599


  • Fixed E305 regression caused by #400; #593

2.1.0 (2016-11-04)


  • Change all references to the pep8 project to say pycodestyle; #530


  • Report E302 for blank lines before an "async def"; #556
  • Update our list of tested and supported Python versions which are 2.6, 2.7, 3.2, 3.3, 3.4 and 3.5 as well as the nightly Python build and PyPy.
  • Report E742 and E743 for functions and classes badly named 'l', 'O', or 'I'.
  • Report E741 on 'global' and 'nonlocal' statements, as well as prohibited single-letter variables.
  • Deprecated use of [pep8] section name in favor of [pycodestyle]; #591
  • Report E722 when bare except clause is used; #579


  • Fix opt_type AssertionError when using Flake8 2.6.2 and pycodestyle; #561
  • Require two blank lines after toplevel def, class; #536
  • Remove accidentally quadratic computation based on the number of colons. This will make pycodestyle faster in some cases; #314

2.0.0 (2016-05-31)


  • Repository renamed to pycodestyle; Issue #466 / #481.
  • Added joint Code of Conduct as member of PyCQA; #483


  • Added tox test support for Python 3.5 and pypy3
  • Added check E275 for whitespace on from ... import ... lines; #489 / #491
  • Added W503 to the list of codes ignored by default ignore list; #498
  • Removed use of project level .pep8 configuration file; #364


  • Fixed bug with treating ~ operator as binary; #383 / #384
  • Identify binary operators as unary; #484 / #485

1.7.0 (2016-01-12)



  • Reverted the fix in #368, "options passed on command line are only ones accepted" feature. This has many unintended consequences in pep8 and flake8 and needs to be reworked when I have more time.
  • Added support for Python 3.5. (Issue #420 & #459)
  • Added support for multi-line config_file option parsing. (Issue #429)
  • Improved parameter parsing. (Issues #420 & #456)


  • Fixed BytesWarning on Python 3. (Issue #459)

1.6.2 (2015-02-15)


  • Added check for breaking around a binary operator. (Issue #197, Pull #305)


  • Restored config_file parameter in process_options(). (Issue #380)

1.6.1 (2015-02-08)


  • Assign variables before referenced. (Issue #287)


  • Exception thrown due to unassigned local_dir variable. (Issue #377)

1.6.0 (2015-02-06)


  • Ian Lee <ianlee1521@gmail.com> joined the project as a maintainer.


  • Report E731 for lambda assignment. (Issue #277)
  • Report E704 for one-liner def instead of E701. Do not report this error in the default configuration. (Issue #277)
  • Replace codes E111, E112 and E113 with codes E114, E115 and E116 for bad indentation of comments. (Issue #274)
  • Report E266 instead of E265 when the block comment starts with multiple #. (Issue #270)
  • Report E402 for import statements not at the top of the file. (Issue #264)
  • Do not enforce whitespaces around ** operator. (Issue #292)
  • Strip whitespace from around paths during normalization. (Issue #339 / #343)
  • Update --format documentation. (Issue #198 / Pull Request #310)
  • Add .tox/ to default excludes. (Issue #335)
  • Do not report E121 or E126 in the default configuration. (Issues #256 / #316)
  • Allow spaces around the equals sign in an annotated function. (Issue #357)
  • Allow trailing backslash if in an inline comment. (Issue #374)
  • If --config is used, only that configuration is processed. Otherwise, merge the user and local configurations are merged. (Issue #368 / #369)

Bug fixes:

  • Don't crash if Checker.build_tokens_line() returns None. (Issue #306)
  • Don't crash if os.path.expanduser() throws an ImportError. (Issue #297)
  • Missing space around keyword parameter equal not always reported, E251. (Issue #323)
  • Fix false positive E711/E712/E713. (Issues #330 and #336)
  • Do not skip physical checks if the newline is escaped. (Issue #319)
  • Flush sys.stdout to avoid race conditions with printing. See flake8 bug: https://gitlab.com/pycqa/flake8/issues/17 for more details. (Issue #363)

1.5.7 (2014-05-29)

Bug fixes:

  • Skip the traceback on "Broken pipe" signal. (Issue #275)
  • Do not exit when an option in setup.cfg or tox.ini is not recognized.
  • Check the last line even if it does not end with a newline. (Issue #286)
  • Always open files in universal newlines mode in Python 2. (Issue #288)

1.5.6 (2014-04-14)

Bug fixes:

  • Check the last line even if it has no end-of-line. (Issue #273)

1.5.5 (2014-04-10)

Bug fixes:

  • Fix regression with E22 checks and inline comments. (Issue #271)

1.5.4 (2014-04-07)

Bug fixes:

  • Fix negative offset with E303 before a multi-line docstring. (Issue #269)

1.5.3 (2014-04-04)

Bug fixes:

  • Fix wrong offset computation when error is on the last char of a physical line. (Issue #268)

1.5.2 (2014-04-04)


  • Distribute a universal wheel file.

Bug fixes:

  • Report correct line number for E303 with comments. (Issue #60)
  • Do not allow newline after parameter equal. (Issue #252)
  • Fix line number reported for multi-line strings. (Issue #220)
  • Fix false positive E121/E126 with multi-line strings. (Issue #265)
  • Fix E501 not detected in comments with Python 2.5.
  • Fix caret position with --show-source when line contains tabs.

1.5.1 (2014-03-27)

Bug fixes:

  • Fix a crash with E125 on multi-line strings. (Issue #263)

1.5 (2014-03-26)


  • Report E129 instead of E125 for visually indented line with same indent as next logical line.  (Issue #126)
  • Report E265 for space before block comment. (Issue #190)
  • Report E713 and E714 when operators not in and is not are recommended. (Issue #236)
  • Allow long lines in multiline strings and comments if they cannot be wrapped. (Issue #224).
  • Optionally disable physical line checks inside multiline strings, using # noqa. (Issue #242)
  • Change text for E121 to report "continuation line under-indented for hanging indent" instead of indentation not being a multiple of 4.
  • Report E131 instead of E121 / E126 if the hanging indent is not consistent within the same continuation block.  It helps when error E121 or E126 is in the ignore list.
  • Report E126 instead of E121 when the continuation line is hanging with extra indentation, even if indentation is not a multiple of 4.

Bug fixes:

  • Allow the checkers to report errors on empty files. (Issue #240)
  • Fix ignoring too many checks when --select is used with codes declared in a flake8 extension. (Issue #216)
  • Fix regression with multiple brackets. (Issue #214)
  • Fix StyleGuide to parse the local configuration if the keyword argument paths is specified. (Issue #246)
  • Fix a false positive E124 for hanging indent. (Issue #254)
  • Fix a false positive E126 with embedded colon. (Issue #144)
  • Fix a false positive E126 when indenting with tabs. (Issue #204)
  • Fix behaviour when exclude is in the configuration file and the current directory is not the project directory. (Issue #247)
  • The logical checks can return None instead of an empty iterator. (Issue #250)
  • Do not report multiple E101 if only the first indentation starts with a tab. (Issue #237)
  • Fix a rare false positive W602. (Issue #34)

1.4.6 (2013-07-02)


  • Honor # noqa for errors E711 and E712. (Issue #180)
  • When both a tox.ini and a setup.cfg are present in the project directory, merge their contents.  The tox.ini file takes precedence (same as before). (Issue #182)
  • Give priority to --select over --ignore. (Issue #188)
  • Compare full path when excluding a file. (Issue #186)
  • New option --hang-closing to switch to the alternative style of closing bracket indentation for hanging indent.  Add error E133 for closing bracket which is missing indentation. (Issue #103)
  • Accept both styles of closing bracket indentation for hanging indent. Do not report error E123 in the default configuration. (Issue #103)

Bug fixes:

  • Do not crash when running AST checks and the document contains null bytes. (Issue #184)
  • Correctly report other E12 errors when E123 is ignored. (Issue #103)
  • Fix false positive E261/E262 when the file contains a BOM. (Issue #193)
  • Fix E701, E702 and E703 not detected sometimes. (Issue #196)
  • Fix E122 not detected in some cases. (Issue #201 and #208)
  • Fix false positive E121 with multiple brackets. (Issue #203)

1.4.5 (2013-03-06)

  • When no path is specified, do not try to read from stdin.  The feature was added in 1.4.3, but it is not supported on Windows.  Use - filename argument to read from stdin.  This usage is supported since 1.3.4. (Issue #170)
  • Do not require setuptools in setup.py.  It works around an issue with pip and Python 3. (Issue #172)
  • Add __pycache__ to the ignore list.
  • Change misleading message for E251. (Issue #171)
  • Do not report false E302 when the source file has a coding cookie or a comment on the first line. (Issue #174)
  • Reorganize the tests and add tests for the API and for the command line usage and options. (Issues #161 and #162)
  • Ignore all checks which are not explicitly selected when select is passed to the StyleGuide constructor.

1.4.4 (2013-02-24)

  • Report E227 or E228 instead of E225 for whitespace around bitwise, shift or modulo operators. (Issue #166)
  • Change the message for E226 to make clear that it is about arithmetic operators.
  • Fix a false positive E128 for continuation line indentation with tabs.
  • Fix regression with the --diff option. (Issue #169)
  • Fix the TestReport class to print the unexpected warnings and errors.

1.4.3 (2013-02-22)

  • Hide the --doctest and --testsuite options when installed.
  • Fix crash with AST checkers when the syntax is invalid. (Issue #160)
  • Read from standard input if no path is specified.
  • Initiate a graceful shutdown on Control+C.
  • Allow changing the checker_class for the StyleGuide.

1.4.2 (2013-02-10)

  • Support AST checkers provided by third-party applications.
  • Register new checkers with register_check(func_or_cls, codes).
  • Allow constructing a StyleGuide with a custom parser.
  • Accept visual indentation without parenthesis after the if statement. (Issue #151)
  • Fix UnboundLocalError when using # noqa with continued lines. (Issue #158)
  • Re-order the lines for the StandardReport.
  • Expand tabs when checking E12 continuation lines. (Issue #155)
  • Refactor the testing class TestReport and the specific test functions into a separate test module.

1.4.1 (2013-01-18)

  • Allow sphinx.ext.autodoc syntax for comments. (Issue #110)
  • Report E703 instead of E702 for the trailing semicolon. (Issue #117)
  • Honor # noqa in addition to # nopep8. (Issue #149)
  • Expose the OptionParser factory for better extensibility.

1.4 (2012-12-22)

  • Report E226 instead of E225 for optional whitespace around common operators (*, **, /, + and -).  This new error code is ignored in the default configuration because PEP 8 recommends to "use your own judgement". (Issue #96)
  • Lines with a # nopep8 at the end will not issue errors on line length E501 or continuation line indentation E12*. (Issue #27)
  • Fix AssertionError when the source file contains an invalid line ending "\r\r\n". (Issue #119)
  • Read the [pep8] section of tox.ini or setup.cfg if present. (Issue #93 and #141)
  • Add the Sphinx-based documentation, and publish it on https://pycodestyle.readthedocs.io/. (Issue #105)

1.3.4 (2012-12-18)

  • Fix false positive E124 and E128 with comments. (Issue #100)
  • Fix error on stdin when running with bpython. (Issue #101)
  • Fix false positive E401. (Issue #104)
  • Report E231 for nested dictionary in list. (Issue #142)
  • Catch E271 at the beginning of the line. (Issue #133)
  • Fix false positive E126 for multi-line comments. (Issue #138)
  • Fix false positive E221 when operator is preceded by a comma. (Issue #135)
  • Fix --diff failing on one-line hunk. (Issue #137)
  • Fix the --exclude switch for directory paths. (Issue #111)
  • Use - filename to read from standard input. (Issue #128)

1.3.3 (2012-06-27)

  • Fix regression with continuation line checker. (Issue #98)

1.3.2 (2012-06-26)

  • Revert to the previous behaviour for --show-pep8: do not imply --first. (Issue #89)
  • Add E902 for IO errors. (Issue #87)
  • Fix false positive for E121, and missed E124. (Issue #92)
  • Set a sensible default path for config file on Windows. (Issue #95)
  • Allow verbose in the configuration file. (Issue #91)
  • Show the enforced max-line-length in the error message. (Issue #86)

1.3.1 (2012-06-18)

  • Explain which configuration options are expected.  Accept and recommend the options names with hyphen instead of underscore. (Issue #82)
  • Do not read the user configuration when used as a module (except if config_file=True is passed to the StyleGuide constructor).
  • Fix wrong or missing cases for the E12 series.
  • Fix cases where E122 was missed. (Issue #81)

1.3 (2012-06-15)


The internal API is backwards incompatible.

  • Remove global configuration and refactor the library around a StyleGuide class; add the ability to configure various reporters. (Issue #35 and #66)
  • Read user configuration from ~/.config/pep8 and local configuration from ./.pep8. (Issue #22)
  • Fix E502 for backslash embedded in multi-line string. (Issue #68)
  • Fix E225 for Python 3 iterable unpacking (PEP 3132). (Issue #72)
  • Enable the new checkers from the E12 series in the default configuration.
  • Suggest less error-prone alternatives for E712 errors.
  • Rewrite checkers to run faster (E22, E251, E27).
  • Fixed a crash when parsed code is invalid (too many closing brackets).
  • Fix E127 and E128 for continuation line indentation. (Issue #74)
  • New option --format to customize the error format. (Issue #23)
  • New option --diff to check only modified code.  The unified diff is read from STDIN.  Example: hg diff | pep8 --diff (Issue #39)
  • Correctly report the count of failures and set the exit code to 1 when the --doctest or the --testsuite fails.
  • Correctly detect the encoding in Python 3. (Issue #69)
  • Drop support for Python 2.3, 2.4 and 3.0. (Issue #78)

1.2 (2012-06-01)

  • Add E121 through E128 for continuation line indentation.  These checks are disabled by default.  If you want to force all checks, use switch --select=E,W.  Patch by Sam Vilain. (Issue #64)
  • Add E721 for direct type comparisons. (Issue #47)
  • Add E711 and E712 for comparisons to singletons. (Issue #46)
  • Fix spurious E225 and E701 for function annotations. (Issue #29)
  • Add E502 for explicit line join between brackets.
  • Fix E901 when printing source with --show-source.
  • Report all errors for each checker, instead of reporting only the first occurrence for each line.
  • Option --show-pep8 implies --first.

1.1 (2012-05-24)

  • Add E901 for syntax errors. (Issues #63 and #30)
  • Add E271, E272, E273 and E274 for extraneous whitespace around keywords. (Issue #57)
  • Add tox.ini configuration file for tests. (Issue #61)
  • Add .travis.yml configuration file for continuous integration. (Issue #62)

1.0.1 (2012-04-06)

  • Fix inconsistent version numbers.

1.0 (2012-04-04)

  • Fix W602 raise to handle multi-char names. (Issue #53)

0.7.0 (2012-03-26)

  • Now --first prints only the first occurrence of each error. The --repeat flag becomes obsolete because it is the default behaviour. (Issue #6)
  • Allow specifying --max-line-length. (Issue #36)
  • Make the shebang more flexible. (Issue #26)
  • Add testsuite to the bundle. (Issue #25)
  • Fixes for Jython. (Issue #49)
  • Add PyPI classifiers. (Issue #43)
  • Fix the --exclude option. (Issue #48)
  • Fix W602, accept raise with 3 arguments. (Issue #34)
  • Correctly select all tests if DEFAULT_IGNORE == ''.

0.6.1 (2010-10-03)

  • Fix inconsistent version numbers. (Issue #21)

0.6.0 (2010-09-19)

  • Test suite reorganized and enhanced in order to check more failures with fewer test files.  Read the run_tests docstring for details about the syntax.
  • Fix E225: accept print >>sys.stderr, "..." syntax.
  • Fix E501 for lines containing multibyte encoded characters. (Issue #7)
  • Fix E221, E222, E223, E224 not detected in some cases. (Issue #16)
  • Fix E211 to reject v = dic['a'] ['b']. (Issue #17)
  • Exit code is always 1 if any error or warning is found. (Issue #10)
  • --ignore checks are now really ignored, especially in conjunction with --count. (Issue #8)
  • Blank lines with spaces yield W293 instead of W291: some developers want to ignore this warning and indent the blank lines to paste their code easily in the Python interpreter.
  • Fix E301: do not require a blank line before an indented block. (Issue #14)
  • Fix E203 to accept NumPy slice notation a[0, :]. (Issue #13)
  • Performance improvements.
  • Fix decoding and checking non-UTF8 files in Python 3.
  • Fix E225: reject True+False when running on Python 3.
  • Fix an exception when the line starts with an operator.
  • Allow a new line before closing ), } or ]. (Issue #5)

0.5.0 (2010-02-17)

  • Changed the --count switch to print to sys.stderr and set exit code to 1 if any error or warning is found.
  • E241 and E242 are removed from the standard checks. If you want to include these checks, use switch --select=E,W. (Issue #4)
  • Blank line is not mandatory before the first class method or nested function definition, even if there's a docstring. (Issue #1)
  • Add the switch --version.
  • Fix decoding errors with Python 3. (Issue #13 [1])
  • Add --select option which is mirror of --ignore.
  • Add checks E261 and E262 for spaces before inline comments.
  • New check W604 warns about deprecated usage of backticks.
  • New check W603 warns about the deprecated operator <>.
  • Performance improvement, due to rewriting of E225.
  • E225 now accepts:

    • no whitespace after unary operator or similar. (Issue #9 [1])
    • lambda function with argument unpacking or keyword defaults.
  • Reserve "2 blank lines" for module-level logical blocks. (E303)
  • Allow multi-line comments. (E302, issue #10 [1])

0.4.2 (2009-10-22)

  • Decorators on classes and class methods are OK now.

0.4 (2009-10-20)

  • Support for all versions of Python from 2.3 to 3.1.
  • New and greatly expanded self tests.
  • Added --count option to print the total number of errors and warnings.
  • Further improvements to the handling of comments and blank lines. (Issue #1 [1] and others changes.)
  • Check all py files in directory when passed a directory (Issue #2 [1]). This also prevents an exception when traversing directories with non *.py files.
  • E231 should allow commas to be followed by ). (Issue #3 [1])
  • Spaces are no longer required around the equals sign for keyword arguments or default parameter values.

These issues refer to the previous issue tracker.

0.3.1 (2009-09-14)

  • Fixes for comments: do not count them when checking for blank lines between items.
  • Added setup.py for pypi upload and easy_installability.

0.2 (2007-10-16)

  • Loads of fixes and improvements.

0.1 (2006-10-01)

Created by Johann C. Rocholl.

Maintained by Florent Xicluna and Ian Lee.

The pycodestyle library is provided under the terms and conditions of the Expat license:

# Permission is hereby granted, free of charge, to any person
# obtaining a copy of this software and associated documentation files
# (the "Software"), to deal in the Software without restriction,
# including without limitation the rights to use, copy, modify, merge,
# publish, distribute, sublicense, and/or sell copies of the Software,
# and to permit persons to whom the Software is furnished to do so,
# subject to the following conditions:
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.


Johann C. Rocholl, Florent Xicluna, Ian Lee


Jun 07, 2024 2.11