pep8 - Python style guide checker
pep8 is a tool to check your Python code against some of the style
conventions in PEP 8
_.
.. _PEP 8: http://www.python.org/dev/peps/pep-0008/
Features
-
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 pep8.py file for this purpose.
-
Comes with a comprehensive test suite.
Installation
You can install, upgrade, uninstall pep8.py with these commands::
$ pip install pep8
$ pip install --upgrade pep8
$ pip uninstall pep8
There's also a package for Debian/Ubuntu, but it's not always the
latest version.
Example usage and output
::
$ pep8 --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:222:34: W602 deprecated form of raising exception
optparse.py:347:31: E211 whitespace before '('
optparse.py:357:17: E201 whitespace after '{'
optparse.py:472:29: E221 multiple spaces before operator
optparse.py:544:21: W601 .has_key() is deprecated, use 'in'
You can also make pep8.py show the source code for each error, and
even the relevant text from PEP 8::
$ pep8 --show-source --show-pep8 testsuite/E40.py
testsuite/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::
$ pep8 --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)
612 W601 .has_key() is deprecated, use 'in'
1188 W602 deprecated form of raising exception
Links
.. image:: https://api.travis-ci.org/PyCQA/pep8.png?branch=master
:target: https://travis-ci.org/PyCQA/pep8
:alt: Build status
.. image:: https://pypip.in/wheel/pep8/badge.png?branch=master
:target: https://pypi.python.org/pypi/pep8
:alt: Wheel Status
Changelog
1.7.1 (2017-10-22)
Changes:
- Prominently note via warning message that the tool is no longer released as
pep8
and will only be fixed in the pycodestyle
package
1.7.0 (2016-01-12)
Announcements:
Changes:
- 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)
Bugs:
- Fixed BytesWarning on Python 3. (Issue #459)
1.6.2 (2015-02-15)
Changes:
- Added check for breaking around a binary operator. (Issue #197, Pull #305)
Bugs:
- Restored config_file parameter in process_options(). (Issue #380)
1.6.1 (2015-02-08)
Changes:
- Assign variables before referenced. (Issue #287)
Bugs:
- Exception thrown due to unassigned
local_dir
variable. (Issue #377)
1.6.0 (2015-02-06)
News:
Changes:
-
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)
Changes:
- 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)
Changes:
-
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)
Changes:
-
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 to change 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 to construct 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 http://pep8.readthedocs.org/. (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)
.. warning::
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 to specify --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:
-
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.
.. [1] These issues refer to the previous issue tracker
__.
.. __: http://github.com/cburroughs/pep8.py/issues
0.3.1 (2009-09-14)
0.2 (2007-10-16)
- Loads of fixes and improvements.
0.1 (2006-10-01)