python判断素数

Question

判断是否为素数，如果是1的话输出(1不是素数，1可以被1整除)

Answer 1

代码如下：

val = int(input("Enter a number: "))
flag = 0
if val == 1:
    print("%d is not prime."%val)
    print("1 is divisible by 1.")
else:
    for i in range(2,val):
        if val%i == 0:
            if flag == 0:
                print("%d is not prime."%val)
                print("%d is divisible by %d." % (val, i))
                flag = 1
            else:
                print("%d is divisible by %d."%(val,i))

    if flag == 0:
        print("%d is prime."%val)