As per PEP8:
__all__ statements in Python code should go after
from __future__ import absolute_import, division, print_function but before any other import statements. The Python style guide has been updated accordingly. Formerly we asked that
__all__ statements come after all imports (following an older version of PEP8).
Note that some old versions of the
flake8 linter will complain about this. Please update your
flake8 if necessary.