Flake8 meet isort

Use isort to check if the imports on your python files are sorted the way you expect.

Add an .isort.cfg to define how you want your imports sorted and run flake8 as you usually do.

See isort documentation for .isort.cfg available options.


Install with pip:

$ pip install flake8-isort

Install with conda:

$ conda install -c conda-forge flake8-isort


If using the select [option from flake8]( be sure to enable the I category as well, see below for the specific error codes reported by flake8-isort.

Error codes

Error code Description
I001 isort found an import in the wrong position
I002 no configuration found (.isort.cfg or [isort] in configs)
I003 isort expected 1 blank line in imports, found 0
I004 isort found an unexpected blank line in imports
I005 isort found an unexpected missing import


  • Python 2.7, 3.5, 3.6, pypy or pypy3
  • flake8
  • isort

Relation to flake8-import-order

As an alternative to this flake8 plugin, there’s flake8-import-order that could be worth checking out. In contrast to this plugin that defers all logic to isort, the flake8-import-order comes bundled with it’s own logic.

flake8-import-order comes with a few predefined set of styles meanwhile this plugin can be customized a bit more. But the biggest difference could lie in that flake8-isort actually has the corresponding sorting engine isort that can sort the import orders of your existing python files. Meanwhile flake8-import-order has no such corresponding tool, hence big existing projects who want to adopt either would get a more automized experience choosing flake8-isort.


GPL 2.0