DeprecationWarning raised under Python 3.10

[johnthagen]

Description

Way to reproduce

from skimage import exposure

Run with python -Werror using Python 3.10

    from skimage import exposure
.tox/py/lib/python3.10/site-packages/skimage/__init__.py:135: in <module>
    from .data import data_dir
.tox/py/lib/python3.10/site-packages/skimage/data/__init__.py:8: in <module>
    from distutils.version import LooseVersion
/usr/local/lib/python3.10/distutils/__init__.py:19: in <module>
    warnings.warn(_DEPRECATION_MESSAGE,
E   DeprecationWarning: The distutils package is deprecated and slated for removal in Python 3.12. Use setuptools or check PEP 632 for potential alternatives

This code was recently moved in #5996 to:

scikit-image/skimage/data/_fetchers.py

Line 8 in fa43626

from distutils.version import LooseVersion

Probably best would be to search for and replace all usages of distutils.

Version information

# Paste the output of the following python commands
from __future__ import print_function
import sys; print(sys.version)
import platform; print(platform.platform())
import skimage; print(f'scikit-image version: {skimage.__version__}')
import numpy; print(f'numpy version: {numpy.__version__}')

• Python 3.10.0
• python:3.10 Docker image
• scikit-image 0.18.3
• numpy 1.21.4

[grlee77]

Thanks @johnthagen, we recently fixed part of this in the main branch (#6007), but a couple of imports of error classes remain. With the recently released setuptools 59 we can remove those as well. I will make a PR to go ahead and do that via a try/except so that we can still fall back to distutils for users with older setuptools.