how to print contents of PYTHONPATH

I suggest not to rely on the raw PYTHONPATH because it can vary depending on the OS.

Instead of the PYTHONPATH value in the os.environ dict, use sys.path from the sys module. This is preferrrable, because it is platform independent:

import sys
print(sys.path)

The value of sys.path is initialized from the environment variable PYTHONPATH, plus an installation-dependent default (depending on your OS). For more info see

https://docs.python.org/2/library/sys.html#sys.path

https://docs.python.org/3/library/sys.html#sys.path