TypeError: unsupported operand type(s) for -: '

问题:

New to python and programing how come I\'m getting this error?

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)

回答1:

1. The reason this is failing is because (Python 3) input returns a string. To convert it to an integer, use int(some_string).

2. You do not typically keep track of indices manually in Python. A better way to implement such a function would be

   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. I changed your API above a bit. It seems to me that n should be the number of times and s should be the string.

回答2:

For future reference Python is strongly typed. Unlike other dynamic languages, it will not automagically cast objects from one type or the other (say from str to int) so you must do this yourself. You\'ll like that in the long-run, trust me!