[Python-ideas] the Quantity pattern

[Robert Kern]

On 2010-03-02 12:35 PM, Bill Janssen wrote:
> I was looking at Martin Fowler's Quantity pattern earlier.
>
> http://martinfowler.com/ap2/quantity.html
>
> I remember writing this up as an idea for Fortran back in the early
> 80's, only to find a CACM paper from 1978 exploring the idea:
> "Incorporation of Units into Programming Languages", Karr&  Loveman, May
> 1978.
>
> But it would still be a cool idea for Python.  Perhaps it's already
> there and I haven't noticed?

Tons of implementations (in no particular order):

http://pypi.python.org/pypi/quantities/
http://pypi.python.org/pypi/Unum/
http://pypi.python.org/pypi/magnitude/
http://pypi.python.org/pypi/units/
http://pypi.python.org/pypi/ScientificPython/
http://pypi.python.org/pypi/SciMath/

And quite a few more that are part of other packages or otherwise not on PyPI. 
It's ridiculously easy to write something that what people think are the common 
cases and so everyone does. It's a lot harder to write something that robustly 
handles what are actually common cases (absolute temperature scales, logarithmic 
scales, etc.).

-- 
Robert Kern

"I have come to believe that the whole world is an enigma, a harmless enigma
  that is made terrible by our own mad attempt to interpret it as though it had
  an underlying truth."
   -- Umberto Eco