中断嵌套的 for 循环后继续 while 循环

Question

在满足嵌套 for 循环中的某些条件后，我正在寻找一种更 Pythonic 的方式来继续 while 循环。对我有用的非常笨重的代码是：

tens = ['30','40','50','60','70','80','90','00']
z=0
while z==0:
    num = input('Please enter a number: ')
    z=1    
    for x in tens:
        if num[0]=='0' or x in num:
            print('That was an invalid selection, please try again.\n')
            z=0  # There has GOT to be a better way to do this!
            break
print(num+' works, Thank You!')

我可以使用 this question 中回答的 try/except ：

tens = ['30','40','50','60','70','80','90','00']
while True:
    num = input('Please enter a number: ')  
    try:
        for x in tens:
            if num[0]=='0' or x in num:
                print('That was an invalid selection, please try again.\n')
                raise StopIteration
    except:
        continue
    break
print(num+' works, Thank You!')

我面临的挑战是

a) 当 if 满足时继续 while 循环（请求新的输入）（换句话说，在同一步骤中中断 for 循环并继续 while 循环）

b) 对每个新输入进行测试，从头开始运行 tens 迭代。

注意：这个问题与 Reddit Challenge #246 Letter Splits

更新：结合 Håken Lid 提供的答案，代码变为

tens = ['30','40','50','60','70','80','90','00']
while True:
    num = input('Please enter a number: ')
    if num[0]=='0' or any(t in num for t in tens):
        print('That was an invalid selection, please try again.\n')
        continue
    break
print(num+' works, Thank You!')

我还没有解决“从嵌套的 for 循环中断/继续”的问题，但是用 any() 函数替换循环对我来说肯定有用。

Answer 1

在大多数情况下，嵌套循环是糟糕的设计。

你的函数总是应该尽可能的小。应用该规则，您将永远不会违反 SOLID 的第一条规则（单一责任原则）。

您的代码可能如下所示：

tens = ['30','40','50','60','70','80','90','00']

def main():
    while 1:
        num = input('Please enter a number: ')
        if nested_test(num):
            print('That was an invalid selection, please try again.\n')
            break

def nested_test(num):
    for x in tens:
        if <some test>:
            return True

Answer 2

不需要您的for 循环。只需使用in 关键字。但除此之外，您对break 的使用也很好。

tens = ['30','40','50','60','70','80','90','00']
while True:
    num = input('Please enter a number: ')
    if num in tens:
       break
    print('That was invalid selection, please try again.\n')
print(num+' works, Thank You!')