Recently I am using Python module os, when I tried to change the permission of a file, I did not get the expected result. For example, I intended to change the permission to
Found this on a different forum
If you're wondering why that leading zero is important, it's because permissions are set as an octal integer, and Python automagically treats any integer with a leading zero as octal. So os.chmod("file", 484) (in decimal) would give the same result.
What you are doing is passing 664 which in octal is 1230
In your case you would need
os.chmod("/tmp/test_file", 436)
[Update] Note, for Python 3 you have prefix with 0o (zero oh). E.G, 0o666