Boost.Python requires Python 2.2 [1] or newer.
[1] Note that although we tested earlier versions of Boost.Python with Python 2.2, and we don't think we've done anything to break compatibility, this release of Boost.Python may not have been tested with versions of Python earlier than 2.4, so we're not 100% sure that python 2.2 and 2.3 are supported.