The python-cdecimal package is a fast drop-in replacement for the decimal
module in Python's standard library.

Both modules provide complete implementations of Mike Cowlishaw/IBM's General
Decimal Arithmetic Specification.

Since cdecimal is compatible with decimal.py, the official documentation is
valid: http://docs.python.org/library/decimal.html

For the few remaining differences, see:
http://www.bytereef.org/mpdecimal/doc/cdecimal/index.html

cdecimal has been integrated into CPython 3.3, where it supersedes
the pure Python version.