python - 您能检查一下 "unsupported operand type(s) for -: ' str' 和 'int' "

Question

请您检查一下这段代码，为什么 python 中出现“unsupported operand type(s) for -: 'str' and 'int'”这个错误。

代码:

def missing_char(str, n):
  check = len(str -1)
  if check < n or n < 0:
      return False
  else:
      front = str[:n]
      back = str[n+1:]
      return front + back

Answer 1

你把)放在了错误的地方，- 1应该在它的外面:

def missing_char(str, n):
  check = len(str) - 1
  if check < n or n < 0:
      return False
  else:
      front = str[:n]
      back = str[n+1:]
      return front + back