Unfortunately, the world of Python arrays is (or better: was) a little complicated and parts of the history still affects the Debian packages now, so this page tries to explain how it works. But in short: just use python-numpy, it contains both the newest NumPy and f2py.
python-numpy is part of the DPMT.
First, there was Numeric. Then people at the Space Telescope Science Institute (STScI) created Numarray, to overcome some limitations with Numeric. Then Travis Oliphant decided to merge improvements from numarray, while retaining the structure of Numeric and the new project is called NumPy.
Debian packages now
- builds: python-numpy, python-numpy-dbg, python-numpy-ext, python-numpy-dev, python-numpy-doc
use this package, it's the most recent NumPy and it also contains the newest f2py
See also python-scipy for information about SciPy packages in Debian.