How do you determine if an IP address is private, in Python?

Question

In Python, what is the best way to determine if an IP address (e.g., '127.0.0.1' or '10.98.76.6') is on a private network? The code does not sound difficult to write. But there may be more edge cases than are immediately apparent, and there's IPv6 support to consider, etc. Is there an existing library that does it?

Answer 1

Since Python 3.3 there is an ipaddress module in the stdlib that you can use.

>>> import ipaddress
>>> ipaddress.ip_address('192.168.0.1').is_private
True

If using Python 2.6 or higher I would strongly recommend to use a backport of this module.