Pysolar is a collection of Python libraries for simulating the irradiation of any point on earth by the sun. It includes code for extremely precise ephemeris calculations, and more
Pysolar has two parts:
Pysolar used to be hosted at Sourceforge, but since March 2008, it's been hosted at Github. Releases 0.2.0 and previous are still available on Sourceforge, but you should not use them for anything new-- all versions before 0.4.1 have known, albeit minor, bugs.
Release 0.4.3 (If you're not sure, download this one.)
Pysolar requires Python, which comes preinstalled on most Unix
machines, including Apple's OS X. You can check to see if you have it
installed on a Unix machine by typing
python at a command prompt. If the result is something like
Python 2.5.1c1 (release25-maint, Apr 12 2007, 21:00:25)
you have Python. (You can escape from the Python prompt with Ctrl-D.)
[GCC 4.1.2 (Ubuntu 4.1.2-0ubuntu4)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
If the result is more like
bash: python: command not found
you probably don't have Python.
If you need to, you can download Python fromthe Python.org download page.