The imp module is deprecated since Python 3.4. In Python 3.4, imp uses a PendingDeprecationWarning, and Python 3.5... hum, still a PendingDeprecationWarning. It was not supposed to become a real DeprecationWarning?

Anyway, the imp module is still used in some places of the Python stdlib:

Lib/modulefinder.py:14:    import imp
Python/makeopcodetargets.py:9:import imp
Tools/i18n/pygettext.py:159:import imp
Tools/importbench/importbench.py:10:import imp

modulefinder explicitly ignore the warning :-(

with warnings.catch_warnings():
    warnings.simplefilter('ignore', PendingDeprecationWarning)
    import imp