m3-cdecimal 2.3

Fast arbitrary precision correctly-rounded decimal floating point arithmetic.

Overview

The 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.

Testing

Both cdecimal and the underlying library - libmpdec - are extremely well tested. libmpdec is one of the few open source projects with 100% code coverage. cdecimal is rigorously tested against decimal.py.

Short benchmarks

Typical performance gains are between 30x for I/O heavy benchmarks and 80x for numerical programs. In a database benchmark, cdecimal exhibits a speedup of 12x over decimal.py.

	decimal	cdecimal	speedup
pi	42.75s	0.58s	74x
telco	172.19s	5.68s	30x
psycopg	3.57s	0.29s	12x

Documentation

Since cdecimal is compatible with decimal.py, the official documentation is valid. For the few remaining differences, refer to the second link.

• Decimal module

• Differences between cdecimal and decimal

Linux Notes

The build process requires a working C compiler and a full Python install with development headers. Linux distributions often ship the Python header files as a separate package, called python-dev or python-devel.

Install headers on Debian/Ubuntu:

• sudo apt-get install python-dev

Windows Notes

• Binary installers

Links

• cdecimal project homepage

• cdecimal benchmarks