There is a JSON API for PyPI which allows getting data for packages:
http://pypi.python.org/pypi//json http://pypi.python.org/pypi/
Here's Bash one-liner:
curl -sG -H 'Host: pypi.org' -H 'Accept: application/json' https://pypi.org/pypi/numpy/json | awk -F "description\":\"" '{ print $2 }' |cut -d ',' -f 1 # NumPy is a general-purpose array-processing package designed to...