pep8 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 pep8.py file for this purpose.
- Comes with a comprehensive test suite.
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.
$ 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