autopep8 automatically formats Python code to conform to the PEP 8 style guide. It uses the pep8 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 pep8.
From pip:
$ pip install --upgrade autopep8
From easy_install:
$ easy_install -ZU autopep8
autopep8 requires pep8 (>= 1.3.2).
To modify a file in place:
$ autopep8 -i <filename>
Before running autopep8.
import sys, os;
def someone_likes_semicolons( foo = None ,\
bar='bar'):
"""Hello; bye."""; print( 'A'<>foo) #<> is a deprecated form of !=
return 0;
def func11():
a=( 1,2, 3,"a" );
####This is a long comment. This should be wrapped to fit within 72 characters.
x = [a,[100,200,300,9876543210,'This is a long string that goes on and on']]
def func22(): return {True: True}.has_key({'foo': 2}.has_key('foo'));
class UselessClass( object ):
def __init__ ( self, bar ):
#Comments should have a space after the hash.
if bar : bar+=1; bar=bar* bar ; return bar
else:
indentation_in_strings_should_not_be_touched = """
hello
world
"""
raise ValueError, indentation_in_strings_should_not_be_touched
def my_method(self):
print(self);
After running autopep8.
import sys
import os
def someone_likes_semicolons(foo=None,
bar='bar'):
"""Hello; bye."""
print('A' != foo) # <> is a deprecated form of !=
return 0
def func11():
a = (1, 2, 3, "a")
# This is a long comment. This should be wrapped to fit within 72
# characters.
x = [a, [100, 200, 300, 9876543210,
'This is a long string that goes on and on']]
def func22():
return ('foo' in {'foo': 2}) in {True: True}
class UselessClass(object):
def __init__(self, bar):
# Comments should have a space after the hash.
if bar:
bar += 1
bar = bar * bar
return bar
else:
indentation_in_strings_should_not_be_touched = """
hello
world
"""
raise ValueError(indentation_in_strings_should_not_be_touched)
def my_method(self):
print(self)
Options:
Usage: autopep8 [options] [filename [filename ...]] Use filename '-' for stdin. Automatically formats Python code to conform to the PEP 8 style guide. Options: --version show program's version number and exit -h, --help show this help message 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 -r, --recursive run recursively; 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: 100) --exclude=globs exclude files/directories 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) --select=errors fix only these errors/warnings (e.g. E4,W) --max-line-length=n set maximum allowed line length (default: 79) --aggressive enable possibly unsafe changes (E711, E712)
autopep8 fixes the following issues reported by pep8:
E101 - Reindent all lines. E111 - Reindent all lines. 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. E20 - Remove extraneous whitespace. E211 - Remove extraneous whitespace. E22 - Fix extraneous whitespace around keywords. E231 - Add missing whitespace. E241 - Fix extraneous whitespace around keywords. E242 - Remove extraneous whitespace around operator. E251 - Remove whitespace around parameter '=' sign. E26 - Fix spacing after comment hash. 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. E401 - Put imports on separate lines. 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. E702 - Put semicolon-separated compound statement on separate lines. E711 - Fix comparison with None. E712 - Fix comparison with boolean. E721 - Switch to use isinstance(). W191 - Reindent all lines. W291 - Remove trailing whitespace. W293 - Remove trailing whitespace on blank line. W391 - Remove trailing blank lines. W601 - Replace the {}.has_key() form with 'in'. W602 - Fix deprecated form of raising exception. W603 - Replace <> with !=. W604 - Replace backticks with repr().
autopep8 also fixes some issues not found by pep8.
- Format block comments. (This is triggered if
E26
is enabled.) - Correct some non-idiomatic Python code (via
2to3 -f idioms
). (This is triggered ifE712
is enabled.) - Normalize files with mixed line endings.
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>
Large files may also take many more iterations to completely fix. Thus, you may need to increase the maximum number of passes:
$ autopep8 -p 1000 <filename>
By default autopep8 makes only safe 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.) To
enable these sort of aggressive fixes, use the --aggressive
option:
$ autopep8 --aggressive <filename>
--aggressive
will also shorten lines more aggressively.
The simplest way of using autopep8 as a module is via the fix_string()
function.
>>> import autopep8
>>> autopep8.fix_string('x= 123\n')
'x = 123\n'
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 2.6, 2.7, 3.2, and 3.3. 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. In a similar fashion, test/acid_github.py
tests
against Python code in Github repositories.