Implements the null object pattern.

Provides:

• a Null singleton that can be used like None (but is not None and is not equal to None)
• a NullList that returns Null instead of raising IndexError
• a NullDict that returns Null instead of raising KeyError
• a nullify() routine that converts mappings and sequences to the nullified variant
• an unset singleton for clearing up APIs to distinguish between a keyword argument that is set by the user as None and simply not set by the user

Use Bitbucket to report issues:

https://bitbucket.org/ambv/null

The easiest way would be to extract the source tarball and run:

$ python test/test_null.py

• MANIFEST.in will forever be my favourite gotcha of Python packaging
• PEP8-fied the sources

• long overdue Python 3 support

• initial published version

Glued together by Łukasz Langa.