autopep8
autopep8 automatically formats Python code to conform to the PEP 8 style guide. It uses the pycodestyle utility to determine what parts of the code needs to be formatted. autopep8 is capable of fixing most of the formatting issues that can be reported by pycodestyle.
Contents
Installation
From pip:
$ pip install --upgrade autopep8
Consider using the --user option.
Requirements
autopep8 requires pycodestyle.
Usage
To modify a file in place (with aggressive level 2):
$ autopep8 --in-place --aggressive --aggressive <filename>
Before running autopep8.
import math, sys;
def example1():
####This is a long comment. This should be wrapped to fit within 72 characters.
some_tuple=( 1,2, 3,'a' );
some_variable={'long':'Long code lines should be wrapped within 79 characters.',
'other':[math.pi, 100,200,300,9876543210,'This is a long string that goes on'],
'more':{'inner':'This whole logical line should be wrapped.',some_tuple:[1,
20,300,40000,500000000,60000000000000000]}}
return (some_tuple, some_variable)
def example2(): return {'has_key() is deprecated':True}.has_key({'f':2}.has_key(''));
class Example3( object ):
def __init__ ( self, bar ):
#Comments should have a space after the hash.
if bar : bar+=1; bar=bar* bar ; return bar
else:
some_string = """
Indentation in multiline strings should not be touched.
Only actual code should be reindented.
"""
return (sys.path, some_string)After running autopep8.
import math
import sys
def example1():
# This is a long comment. This should be wrapped to fit within 72
# characters.
some_tuple = (1, 2, 3, 'a')
some_variable = {
'long': 'Long code lines should be wrapped within 79 characters.',
'other': [
math.pi,
100,
200,
300,
9876543210,
'This is a long string that goes on'],
'more': {
'inner': 'This whole logical line should be wrapped.',
some_tuple: [
1,
20,
300,
40000,
500000000,
60000000000000000]}}
return (some_tuple, some_variable)
def example2(): return ('' in {'f': 2}) in {'has_key() is deprecated': True}
class Example3(object):
def __init__(self, bar):
# Comments should have a space after the hash.
if bar:
bar += 1
bar = bar * bar
return bar
else:
some_string = """
Indentation in multiline strings should not be touched.
Only actual code should be reindented.
"""
return (sys.path, some_string)Options:
usage: autopep8 [-h] [--version] [-v] [-d] [-i] [--global-config filename]
[--ignore-local-config] [-r] [-j n] [-p n] [-a]
[--experimental] [--exclude globs] [--list-fixes]
[--ignore errors] [--select errors] [--max-line-length n]
[--line-range line line] [--hang-closing] [--exit-code]
[files [files ...]]
Automatically formats Python code to conform to the PEP 8 style guide.
positional arguments:
files files to format or '-' for standard in
optional arguments:
-h, --help show this help message and exit
--version show program's version number and exit
-v, --verbose print verbose messages; multiple -v result in more
verbose messages
-d, --diff print the diff for the fixed source
-i, --in-place make changes to files in place
--global-config filename
path to a global pep8 config file; if this file does
not exist then this is ignored (default:
~/.config/pep8)
--ignore-local-config
don't look for and apply local config files; if not
passed, defaults are updated with any config files in
the project's root directory
-r, --recursive run recursively over directories; must be used with
--in-place or --diff
-j n, --jobs n number of parallel jobs; match CPU count if value is
less than 1
-p n, --pep8-passes n
maximum number of additional pep8 passes (default:
infinite)
-a, --aggressive enable non-whitespace changes; multiple -a result in
more aggressive changes
--experimental enable experimental fixes
--exclude globs exclude file/directory names that match these comma-
separated globs
--list-fixes list codes for fixes; used by --ignore and --select
--ignore errors do not fix these errors/warnings (default:
E226,E24,W50,W690)
--select errors fix only these errors/warnings (e.g. E4,W)
--max-line-length n set maximum allowed line length (default: 79)
--line-range line line, --range line line
only fix errors found within this inclusive range of
line numbers (e.g. 1 99); line numbers are indexed at
1
--hang-closing hang-closing option passed to pycodestyle
--exit-code change to behavior of exit code. default behavior of
return value, 0 is no differences, 1 is error exit.
return 2 when add this option. 2 is exists
differences.
Features
autopep8 fixes the following issues reported by pycodestyle:
E101 - Reindent all lines. E11 - Fix indentation. E121 - Fix indentation to be a multiple of four. E122 - Add absent indentation for hanging indentation. E123 - Align closing bracket to match opening bracket. E124 - Align closing bracket to match visual indentation. E125 - Indent to distinguish line from next logical line. E126 - Fix over-indented hanging indentation. E127 - Fix visual indentation. E128 - Fix visual indentation. E129 - Fix visual indentation. E131 - Fix hanging indent for unaligned continuation line. E133 - Fix missing indentation for closing bracket. E20 - Remove extraneous whitespace. E211 - Remove extraneous whitespace. E22 - Fix extraneous whitespace around keywords. E224 - Remove extraneous whitespace around operator. E225 - Fix missing whitespace around operator. E226 - Fix missing whitespace around arithmetic operator. E227 - Fix missing whitespace around bitwise/shift operator. E228 - Fix missing whitespace around modulo operator. E231 - Add missing whitespace. E241 - Fix extraneous whitespace around keywords. E242 - Remove extraneous whitespace around operator. E251 - Remove whitespace around parameter '=' sign. E252 - Missing whitespace around parameter equals. E26 - Fix spacing after comment hash for inline comments. E265 - Fix spacing after comment hash for block comments. E266 - Fix too many leading '#' for block comments. E27 - Fix extraneous whitespace around keywords. E301 - Add missing blank line. E302 - Add missing 2 blank lines. E303 - Remove extra blank lines. E304 - Remove blank line following function decorator. E305 - Expected 2 blank lines after end of function or class. E306 - Expected 1 blank line before a nested definition. E401 - Put imports on separate lines. E402 - Fix module level import not at top of file E501 - Try to make lines fit within --max-line-length characters. E502 - Remove extraneous escape of newline. E701 - Put colon-separated compound statement on separate lines. E70 - Put semicolon-separated compound statement on separate lines. E711 - Fix comparison with None. E712 - Fix comparison with boolean. E713 - Use 'not in' for test for membership. E714 - Use 'is not' test for object identity. E721 - Use "isinstance()" instead of comparing types directly. E722 - Fix bare except. E731 - Use a def when use do not assign a lambda expression. W291 - Remove trailing whitespace. W292 - Add a single newline at the end of the file. W293 - Remove trailing whitespace on blank line. W391 - Remove trailing blank lines. W503 - Fix line break before binary operator. W504 - Fix line break after binary operator. W605 - Fix invalid escape sequence 'x'. W690 - Fix various deprecated code (via lib2to3).
autopep8 also fixes some issues not found by pycodestyle.
- Correct deprecated or non-idiomatic Python code (via
lib2to3). Use this for making Python 2.7 code more compatible with Python 3. (This is triggered ifW690is enabled.) - Normalize files with mixed line endings.
- Put a blank line between a class docstring and its first method
declaration. (Enabled with
E301.) - Remove blank lines between a function declaration and its docstring. (Enabled
with
E303.)
autopep8 avoids fixing some issues found by pycodestyle.
E112/E113for non comments are reports of bad indentation that break syntax rules. These should not be modified at all.E265, which refers to spacing after comment hash, is ignored if the comment looks like code. autopep8 avoids modifying these since they are not real comments. If you really want to get rid of the pycodestyle warning, consider just removing the commented-out code. (This can be automated via eradicate.)
More advanced usage
By default autopep8 only makes whitespace changes. Thus, by default, it does
not fix E711 and E712. (Changing x == None to x is None may
change the meaning of the program if x has its __eq__ method
overridden.) Nor does it correct deprecated code W6. To enable these
more aggressive fixes, use the --aggressive option:
$ autopep8 --aggressive <filename>
Use multiple --aggressive to increase the aggressiveness level. For
example, E712 requires aggressiveness level 2 (since x == True could be
changed to either x or x is True, but autopep8 chooses the former).
--aggressive will also shorten lines more aggressively. It will also remove
trailing whitespace more aggressively. (Usually, we don't touch trailing
whitespace in docstrings and other multiline strings. And to do even more
aggressive changes to docstrings, use docformatter.)
To enable only a subset of the fixes, use the --select option. For example,
to fix various types of indentation issues:
$ autopep8 --select=E1,W1 <filename>
If the file being fixed is large, you may want to enable verbose progress messages:
$ autopep8 -v <filename>
Passing in --experimental enables the following functionality:
- Shortens code lines by taking its length into account
$ autopep8 --experimental <filename>
Disabling line-by-line
It is possible to disable autopep8 untill it it turned back on again in the file, using autopep8: off and then renabling autopep8: on.
# autopep8: off
[
[23, 23, 13, 43],
[32, 34, 34, 34],
[56, 34, 34, 11],
[10, 10, 10, 10],
]
# autopep8: onfmt: off and fmt: on are also valid.
Use as a module
The simplest way of using autopep8 as a module is via the fix_code()
function:
>>> import autopep8 >>> autopep8.fix_code('x= 123\n') 'x = 123\n'
Or with options:
>>> import autopep8 >>> autopep8.fix_code('print( 123 )\n', ... options={'ignore': ['E']}) 'print( 123 )\n'
Configuration
By default, if $HOME/.config/pycodestyle (~\.pycodestyle in Windows
environment) exists, it will be used as global configuration file.
Alternatively, you can specify the global configuration file with the
--global-config option.
Also, if setup.cfg, tox.ini, .pep8 and .flake8 files exist
in the directory where the target file exists, it will be used as the
configuration file.
pep8, pycodestyle, and flake8 can be used as a section.
configuration file example:
[pycodestyle] max_line_length = 120 ignore = E501
pyproject.toml
autopep8 can also use pyproject.toml.
The section must be [tool.autopep8], and pyproject.toml takes precedence
over any other configuration files.
configuration file example:
[tool.autopep8] max_line_length = 120 ignore = "E501,W6" # or ["E501", "W6"] in-place = true recursive = true aggressive = 3
Usage with pre-commit
autopep8 can be used as a hook for pre-commit.
To add autopep8 as a plugin, add this repo definition to your configuration:
repos:
- repo: https://github.com/hhatto/autopep8
rev: ... # select the tag or revision you want, or run `pre-commit autoupdate`
hooks:
- id: autopep8Testing
Test cases are in test/test_autopep8.py. They can be run directly via
python test/test_autopep8.py or via tox. The latter is useful for
testing against multiple Python interpreters. (We currently test against
CPython versions 3.7, 3.8, 3.9 and 3.10. We also test against PyPy.)
Broad spectrum testing is available via test/acid.py. This script runs
autopep8 against Python code and checks for correctness and completeness of the
code fixes. It can check that the bytecode remains identical.
test/acid_pypi.py makes use of acid.py to test against the latest
released packages on PyPI.
Troubleshooting
pkg_resources.DistributionNotFound
If you are using an ancient version of setuptools, you might encounter
pkg_resources.DistributionNotFound when trying to run autopep8. Try
upgrading setuptools to workaround this setuptools problem:
$ pip install --upgrade setuptools
Use sudo if you are installing to the system.