mass rename files in folders

[wavic]

import os
from sys import argv

path = argv[1] # take the directory from the command line.
for root, dirs, files in os.walk(path):
    for file in files:
        dir = os.path.split(root)[-1]
        os.rename(file, f"{dir}-{file}")

os.walk starts from the 'path' and for each directory from the three returns a tuple:

{the_current_directory,
 a_list_of_all_directories_in_the_current_directory,
 a_list_of_all_files_in_the_current_directory)

So, you just pass the path to the os.walk and for each iteration, you change the names of the 'files' from the tuple (root, dirs, files). 'files' is a list of all files in 'root', which is the current directory during the scan.