Question

为什么我在非常基本的Python脚本中出现此错误？错误是什么意思？

错误：

Traceback (most recent call last):
  File "cab.py", line 16, in <module>
    if cab in line:
TypeError: 'in <string>' requires string as left operand, not int

脚本：

import re
import sys

#loco = sys.argv[1]
cab = 6176
fileZ = open('cabs.txt')
fileZ = list(set(fileZ))

for line in fileZ:
     if cab in line: 
        IPaddr = (line.strip().split())
        print(IPaddr[4])

Answer 1

您只需要将cab设为字符串：

cab = '6176'

如错误消息所示，您无法执行<int> in <string>：

>>> 1 in '123'
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'in <string>' requires string as left operand, not int
>>>

因为integers和strings是两个完全不同的东西，Python不包含隐式类型转换（"Explicit is better than implicit."）。

实际上，如果左操作数也是string类型的话，Python only 允许你使用in运算符和一个类型为string的右操作数：

>>> '1' in '123'  # Works!
True
>>>
>>> [] in '123'
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'in <string>' requires string as left operand, not list
>>>
>>> 1.0 in '123'
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'in <string>' requires string as left operand, not float
>>>
>>> {} in '123'
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'in <string>' requires string as left operand, not dict
>>>

TypeError：＆＃39;在<string>＆＃39;要求字符串作为左操作数，而不是int </string>

1 个答案: