If I Change The Current Working Directory, Why Does __file__ Become Invalid Path?

Executing test.py from /tmp import os print os.path.abspath(__file__) os.chdir('/var') print os.path.abspath(__file__) output: /tmp/test.py /var/test.py I expected the second ou

Solution 1:

Depending on how you invoke the python script, __file__ can be an absolute or a relative path (e.g. python /tmp/test.py for the former and cd /tmp; python test.py for the latter).

So if __file__ is relative, os.path.abspath will use the current working directory as the base directory.

Easy to prove by adding print __file__ to your test script.