Project Euler Practice - Problem 1 (python)

problem1.py

#!/usr/bin/python
# project euler problem 1
#all the natural numbers below 10 are multiples of 3 or 5
# 3,5,6,9 their sum is 23
# find the sum of all the multiples of 3 or 5 below 1000

limit = 1000

def main():
    summandr = []
    lim3 = 1 + limit / 3
    lim5 = limit / 5
    for i in range(1, lim3):
        summandr.append( i * 3 )
    for i in range(1,lim5):
        summandr.append( i * 5)
    summandr = set(summandr)
    print sum(summandr)

if __name__ == '__main__':
    main()