py.test plugin to check import ordering using isort

Support

Python 3.7, 3.8, 3.9 and 3.10. pytest>=5.

Usage

install using pip:

pip install pytest-isort

Activate isort checks when calling py.test:

py.test --isort

This will execute an isort check against every .py file (if its not ignored).

Example

Given you have some files with incorrect sorted imports:

# content of file1.py

import os
import sys
import random

# content of file2.py

import json
import sys
import os

If you run py.test and activate the isort plugin you'll se something like this:

$ py.test --isort
========================= test session starts ==========================
platform darwin -- Python 2.7.9 -- py-1.4.26 -- pytest-2.6.4
plugins: isort
collected 2 items

file1.py F
file2.py F

=============================== FAILURES ===============================
_____________________________ isort-check ______________________________
ERROR: file1.py Imports are incorrectly sorted.

 import os
+import random
 import sys
-import random
_____________________________ isort-check ______________________________
ERROR: file2.py Imports are incorrectly sorted.

 import json
+import os
 import sys
-import os
======================= 2 failed in 0.02 seconds =======================

If you can't change the import ordering for file2.py, you have the option to exclude file2.py from isort checks.

Simply add the isort_ignore setting to your py.test configuration file:

[pytest]
isort_ignore =
    file2.py

Then re-run the tests:

$ py.test --isort
========================= test session starts ==========================
platform darwin -- Python 2.7.9 -- py-1.4.26 -- pytest-2.6.4
plugins: isort
collected 1 items

file1.py F

=============================== FAILURES ===============================
_____________________________ isort-check ______________________________
ERROR: file1.py Imports are incorrectly sorted.

 import os
+import random
 import sys
-import random
======================= 1 failed in 0.02 seconds =======================

As you can see, file2.py is ignored and not checked. Now fix the import ordering in file1.py and re-run the tests:

$ py.test --isort
========================= test session starts ==========================
platform darwin -- Python 2.7.9 -- py-1.4.26 -- pytest-2.6.4
plugins: isort
collected 1 items

file1.py .

======================= 1 passed in 0.01 seconds ======================

Everything is properly again. Congratulations!

If you run your testsuite again and again, py.test will only check changed files to speed up. You see this by adding -rs to your py.test options:

$ py.test --isort -rs
========================= test session starts ==========================
platform darwin -- Python 2.7.9 -- py-1.4.26 -- pytest-2.6.4
plugins: isort
collected 1 items

file1.py s
======================= short test summary info ========================
SKIP [1] pytest_isort.py:145: file(s) previously passed isort checks

====================== 1 skipped in 0.01 seconds ======================

Configuration

You can exclude files from isort checks by using the isort_ignore setting in your py.test configuration file (e.g. pytest.ini):

# content of setup.cfg
[pytest]
isort_ignore =
    docs/conf.py
    *migrations/*.py

This will ignore the conf.py python file inside the docs folder and also ignore any python file in migrations folders.

In addition, excluded files in isort's configuration will be ignored too.

Notes

You can use isort to rewrite your python files and re-order the imports but this is not part of this plugin.