Question

一切似乎都正常运行，除了在运行程序并且数字不是素数时我仍然得到None输出。如果没有“无值”打印，则“ IS PRIME”可以正常工作

def is_prime():

        your_guess = int(input("Choose a number to find out if it's prime..."))

        div = 2
        is_prime = True

        while div < your_guess:
            if your_guess % div == 0:
                is_prime = False
                print ("The Number is not Prime")
                break

            div += 1
        else:
            if is_prime == True:
                return ("The number  is Prime!")

print (is_prime())

Answer 1

def is_prime():
your_guess = int(input("Choose a number to find out if it's prime..."))

div = 2
is_prime = True

while div < your_guess:
    if your_guess % div == 0:
        is_prime = False
        print ("The Number is not Prime")
        break

    div += 1
else:
    if is_prime == True:
        print ("The number  is Prime!")
return is_prime

尝试此操作并检查程序的逻辑。没有返回的原因是因为您在if（is_prime == True）之后使用了return语句。记住return和print是两件事。

Answer 2

一个函数应该为您指定的两个条件返回一些内容。

def is_prime():
your_guess = int(input("Choose a number to find out if it's prime..."))

div = 2
is_prime = True

while div < your_guess:
    if your_guess % div == 0:
        is_prime = False
        return "The Number is not Prime"
    div += 1
else:
    if is_prime == True:
        return ("The number  is Prime!")


print(is_prime())

有条件后返回None而不是print语句

2 个答案: