NumPy is a package that defines a multi-dimensional array object and associated fast math functions that operate on it. It also provides simple routines for linear algebra and fft and sophisticated random-number generation. NumPy replaces both Numeric and Numarray. http://numeric.scipy.org
The documentation for NumPy is being sold for a fee. The link to the free documentation is hard to find due to numpy.sourceforge.net (currently to a broken link). The free documentation is also not included in the distribution. Try here: http://numpy.sourceforge.net/numdoc/