Getting the file extension from a file path in Python

Determine the file extension

os.path.splitext() is used to split the path name into a pair root and ext.

e.g. C:\Users\memyselfandi\projects\file_extension_test\data.csv

is split into C:\Users\memyselfandi\projects\file_extension_test\data and .csv

Here is a working snippet for identifying CSV and XLS:

import os
if os.path.isfile(input_file):
    file_extension = os.path.splitext(input_file)[1].lower()
    if file_extension == ".csv":
        logger.info("It's a CSV")
        # do something with CSV
    elif file_extension == ".xls":
        logger.info("It's an XLS")
        # do something with XLS
    else:
        logger.error("No valid file extension")