Top Numerical Analysis Departments in the World

University of Cambridge Department of Applied Mathematics and Theoretical Physics (DAMTP)
University of Manchester Numerical Analysis and Scientific Computing
Imperial College Applied and Numerical Analysis Group
University of Chicago NAG
KTH Royal Institute of Technology Numerical Analysis Department (dating from 1962). Germund Dahlquist was a key figure in the Numerical Analysis department. The group is also closely associated with the High Performance Computing department. 

Useful Numerical Journals

There are various journals which may be of interest to the programmer experimenting with mathematics. Some noteworthy ones include:

Acta Numerica - "survey papers by leading researchers in numerical analysis and scientific computing". It is edited by Cambridge-based computational mathematician, Arieh Iserles.

SIAM Journal on Numerical Analysis - research on development and analysis of numerical methods

Numerische Mathematik - established in 1959

BIT Numerical Mathematics

Generators in Python

Generators in Python were proposed in PEP 255 and integrated into the language via the yield keyword. Used in conjunction with the while loop, generators can be used create function objects yielding infinite sequences.

Neil Schemenauer is one of the co-authors of the PEP (2 to the power 8, minus 1).

Function Decorators in Python

They can be used to add "attributes" to a Python function. They look like this:

@specialPowers
def myFunction():
    doStuff

Thinking in Java author Bruce Eckel has written an article on Artima on this.

Writing a Recursive Function in Python

Writing a recursive function in Python is the same as writing a recursive function in any language including functional languages. You have to get your base case and recursive case in order.