human
how to get extension from list of files.
assistant
Here is a Python program to get extension from list of files

import os

def get_extension(file_list):
    """Returns the extension of the file."""
    return [os.path.splitext(f)[1] for f in file_list]

# Enter the list of files
file_list = ['file1.txt', 'file2.txt', 'file3.txt']

# Calling the function
print((get_extension(file_list)))

#Example Output
# ['.txt', '.txt', '.txt']

#Remember to inspect code for bugs.