Sum of all multiples of 3 and 5 below 1000

problem.py

sum1 = 0;
for i in range(3,1000):
    if( ((i % 3) == 0) or ((i % 5) == 0) ):
        sum1 += i

print "The sum is",sum1

print sum(x for x in range(3,100))
print sum(y for y in range(3,1000) if not(y%3) or not(y%5))

#print sum(x for x in xrange(1,1000) if x % 3 == 0 or x % 5 == 0)