how do i list a type of file in a directory python code example

Example 1: list files in directory python

import os
print(os.listdir('/path/to/folder/to/list'))

Example 2: python file list

def file_read(fname):
        with open(fname) as f:
                #Content_list is the list that contains the read lines.     
                content_list = f.readlines()
                print(content_list)

file_read(\'test.txt\')