Import order coding standard

PEP8 suggests that:

Imports should be grouped in the following order:

1. standard library imports
2. related third party imports
3. local application/library specific imports

You should put a blank line between each group of imports.

Is there a way to check if the standard is violated anywhere in the package using static code analysis tools, like pylint, pyflakes, pychecker, pep8?

Example of violation:

from my_package import my_module
from django.db import models
import os

Correct way to import:

import os

from django.db import models

from my_package import my_module

The current version of pylint now does this, and reports it as error class C0411.

Update (2016): sbywater has the most recent answer.

Found it! (accidentally, while reading "Hacker's guide to python")

OpenStack Hacking Style Checks project named hacking introduces several unique flake8 extensions. There is hacking_import_groups among them (related commit).

Example:

• requirements

  • tox
  • flake8

  • hacking (from the master branch):

    $ git clone https://github.com/openstack-dev/hacking.git
    $ cd hacking/
    $ python setup.py install
    

• files used in the example

  • tox.ini (we need to tell flake8 that we want to use a custom check)

    [hacking]
    local-check = hacking.core.hacking_import_groups
    

    UPD: with the newest version of hacking the path to the check changed, now it is hacking.checks.imports.hacking_import_groups.

  • test.py (target of the check)

    import requests
    import sys
    from my_module import print_smth
    
    
    print_smth(requests.get('https://google.com'))
    print_smth(sys.version)
    

  • my_module.py (local import used by test.py)

    def print_smth(smth):
        print smth
    

Then, if I run flake8 against test.py:

$ flake8 test.py
test.py:2:1: H305  imports not grouped correctly (requests: third-party, sys: stdlib)
test.py:3:1: H305  imports not grouped correctly (sys: stdlib, my_module.print_smth: project)
test.py:3:1: H306  imports not in alphabetical order (sys, my_module.print_smth)

Then, if I group the imports in the correct order following PEP8:

import sys

import requests

from my_module import print_smth


print_smth(requests.get('https://google.com'))
print_smth(sys.version)

No warnings found:

$ flake8 test.py
$

Hope this will help somebody in the future.