import math
def prime(n):
    t=int(math.sqrt(n)+1)
    if i==2:
        return 1
    for i in range(2,t+1):
        if n%i==0:
            return 0
    return 1

result=0
for i in range(2,2000000):
    if prime(i)==1:
        result=result+i
print(result)

求2000000一下的素数和----Python