Python packages for Astro

NumPy - adds fast multidimensional array management capability to python.
PyEphem - a library to compute sky position of a generic object or Solar System planets.
PyFITS - an advanced library to handle FITS files.
asciitable - a small python library to efficiently manage, of course, ASCII tables.
ATpy - Astronomical tables in python. Both previous library are used by a general python library to manage tables in many formats of interest in astronomy.
matplotlib (freetype , libpng )
gnuplot-py (gnuplot) - gnuplot python wrapper.
PIL - Python Imaging Library.
astLib -  a python library to deal with various astronomical problems (cosmology, WCS for FITS files, etc.).
odict - to create dictionaries saving the insertion order (first inserted, first listed).
fftw - for discrete fast Fourier transform management.
SciPy - the rather complex and heavy package Scientific Python.