python - 类型错误 : unsupported operand type(s) for -: 'str' and 'int'

Question

我怎么会收到这个错误？

我的代码:

def cat_n_times(s, n):
    while s != 0:
        print(n)
        s = s - 1

text = input("What would you like the computer to repeat back to you: ")
num = input("How many times: ")

cat_n_times(num, text)

错误:

TypeError: unsupported operand type(s) for -: 'str' and 'int'

Answer 1

1. 失败的原因是(Python 3)input 返回一个字符串。要将其转换为整数，请使用 int(some_string)。

2. 您通常不会在 Python 中手动跟踪索引。实现这种功能的更好方法是

   def cat_n_times(s, n):
       for i in range(n):
           print(s) 
   
   text = input("What would you like the computer to repeat back to you: ")
   num = int(input("How many times: ")) # Convert to an int immediately.
   
   cat_n_times(text, num)
   

3. 我在上面修改了你的 API。在我看来，n 应该是 number of times 而 s 应该是 string。