get an extension for the filename python with pathlib code example

Example 1: split filename and extension python

>>> import os
>>> filename, file_extension = os.path.splitext('/path/to/somefile.ext')
>>> filename
'/path/to/somefile'
>>> file_extension
'.ext'

Example 2: os extension

>>> os.path.splitext('/a/b.c/d')
('/a/b.c/d', '')