Question

我不了解如何在用户输入中使用for循环。更具体地说，我想创建一个for循环，如果满足条件，则会要求更多用户输入。

例如，我正在考虑做以下事情：

number = input("what is the value")
for number in numbers:
   number = input("what is the value")
   numbers = [1,2,3]
if number = numbers
   print (number)

以上是一个通用代码，我的目标是获取循环的输入（值是什么）。

如果我按照上面显示的方式进行，问题会在开头重复两次。

如果我删除第1行，我的变量是未定义的。如果我稍后删除第3行，那么依赖于数字变量的代码将被取消定义。

有人能告诉我一个更好的方法来解决这个问题吗？

Answer 1

您可以使用while循环

 while True:
   num = raw_input("what is the value ")
   num = int(num)
   number = [1,2,3]
   if num in number:
       pass
   else:
       break

正如你所说num中存在number然后循环将运行，否则它将退出

Answer 2

尝试这个运行5次的简单for循环并询问用户的输入。如果她输入的数字与循环变量匹配，则打印成功消息。快乐编程：）

for i in range(5): #Runs this loop 5 times
    number = input("what is the value ? :")
    if number == i:
        print "You are correct"
    else:
        print "The correct answer is ", i

日志：

what is the value ? :1
The correct answer is  0
what is the value ? :1
You are correct
what is the value ? :2
You are correct
what is the value ? :1
The correct answer is  3
what is the value ? :1
The correct answer is  4

更新：如果你非常喜欢动物

animals = ['cat', 'dog', 'macaw', 'dove']
for ani in animals:
    animal = raw_input("what is the value ? :")
    if animal == ani:
        print "You are correct"
    else:
        print "The correct answer is ", ani

日志：

what is the value ? :dog
The correct answer is  cat
what is the value ? :cat
The correct answer is  dog
what is the value ? :macaw
You are correct
what is the value ? :test
The correct answer is  dove

在Python中使用For循环，用户输入时出错

2 个答案: