Extracting extension from filename in Python

Question

Is there a function to extract the extension from a filename?

Answer 1

Yes. Use os.path.splitext(see Python 2.X documentation or Python 3.X documentation):

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

Unlike most manual string-splitting attempts, os.path.splitext will correctly treat /a/b.c/d as having no extension instead of having extension .c/d, and it will treat .bashrc as having no extension instead of having extension .bashrc:

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