Project Euler - Problem 2

Each new term in the Fibonacci sequence is generated by adding the previous two terms. By starting with 1 and 2, the first 10 terms will be: 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, ...

By considering the terms in the Fibonacci sequence whose values do not exceed four million, find the sum of the even-valued terms.

def SumOfEvenValuedFibbonacciTerms(limit):
sum = 0
a = b = 1
while b < limit:
if not b % 2:
sum += b
a, b = b, a + b
return sum