Fibonacci in python

gistfile1.txt

>>> def fib(n):
...   last = 0
...   current = 1
...   for i in range(n):
...     (last, current) = (current, last + current)
...   return current
...
>>> fib(3)
3
>>> fib(100)
573147844013817084101
>>> fib(30)
1346269
>>> fib(1000)
70330367711422815821835254877183549770181269836358732742604905087154537118196933579742249494562611733487750449241765991088186363265450223647106012053374121273867339111198139373125598767690091902245245323403501