Default is to assume any Python 3 version could be the target, and use a union of all stdlib modules across versions. -python-version: Tells isort to set the known standard library based on the specified Python version.
Profiles include: black, django, pycharm, google, open_stack, plone, attrs, hug. The options used are mainly to be compatible with black (see here): $ isort -multi-line 3 -profile black -python-version 27.
