What is the Python way for recursively setting file permissions?

Question

What's the "python way" to recursively set the owner and group to files in a directory? I could just pass a 'chown -R' command to shell, but I feel like I'm missing something obvious.

I'm mucking about with this:

import os  
path = "/tmp/foo"  
for root, dirs, files in os.walk(path):  
  for momo in dirs:  
    os.chown(momo, 502, 20)

This seems to work for setting the directory, but fails when applied to files. I suspect the files are not getting the whole path, so chown fails since it can't find the files. The error is:

'OSError: [Errno 2] No such file or directory: 'foo.html'

What am I overlooking here?

Answer 1

The dirs and files lists are all always relative to root - i.e., they are the basename() of the files/folders, i.e. they don't have a / in them (or \ on windows). You need to join the dirs/files to root to get their whole path if you want your code to work to infinite levels of recursion:

import os  
path = "/tmp/foo"  
for root, dirs, files in os.walk(path):  
  for momo in dirs:  
    os.chown(os.path.join(root, momo), 502, 20)
  for momo in files:
    os.chown(os.path.join(root, momo), 502, 20)

I'm suprised the shutil module doesn't have a function for this.