Quantities is designed to handle arithmetic and conversions of physical
quantities, which have a magnitude, dimensionality specified by various units,
and possibly an uncertainty. See the tutorial for examples. Quantities builds
on the popular numpy library and is designed to work with numpy ufuncs, many
of which are already supported. Quantities is actively developed, and while
the current features and API are stable, test coverage is incomplete so the
package is not suggested for mission-critical applications.

WWW: https://github.com/python-quantities/python-quantities