当用户输入包含空格时，我的代码显示 ValueError??(Python)

Question

以下代码获取用户输入，然后输出用户输入中每个字母的反向英文字母版本。但是，它只适用于任何仅包含字母的字符串，如果用户输入有空格字符（或符号，但符号对于此代码并不重要），它会显示一个 ValueError。 我如何让它也适用于空间？

import string

#Gets every letter in the alphabet:

alphabets = list(string.ascii_lowercase)

#create some list to do something, will be explained later;

res = []

res2 = []

#Gets user input:

getString = str(input()).lower()

#Gets every letter in the input:

get_all_letters = [x for x in getString]

#Create for loop then find the index of every letter in user input in alphabet, append it to the res list:

for x in range(-1,len(get_all_letters)-1):

  x+=1

  if get_all_letters[x-1] in alphabets:

    m = alphabets.index(get_all_letters[x])

    res.append(m)

#Reverse the alphabet:

reversed_alphabets = alphabets[::-1]

#Create for loop to append every element in the reversed alphabet by given index in the res list to the res2 list:

for x in res:

  res2.append(reversed_alphabets[x])

#Convert the res2 list to string:

n = "".join(res2)

#print it:

print(n)

如果用户在循环外或循环内包含空格，我尝试附加一个空格，它运行但显示意外输出。所以，我决定删除它。这里还有一些输入示例、预期输出和我的输出： 输入：“你好世界” 预期输出：“svool dilow” 我的输出：ValueError: ' ' is not in list.

输入：“猫” 期望输出：“xzg” 我的输出：“wzg”

输入：“cat” 预期输出：“xz g” 我的输出：ValueError: ' ' is not in list.

有办法解决吗？

Answer 1

这里是你的代码修改后可以正常工作，删除了不必要的 -1/+1/-1：

import string

#Gets every letter in the alphabet:
alphabets = string.ascii_lowercase

#create some list to do something, will be explained later;
res = []
res2 = []

#Gets user input:
getString = input().lower()

#Create for loop then find the index of every letter in user input in alphabet, append it to the res list:
for x in range(len(getString)):
  if getString[x] in alphabets:
    m = alphabets.index(getString[x])
    res.append(m)

#Reverse the alphabet:
reversed_alphabets = alphabets[::-1]

#Create for loop to append every element in the reversed alphabet by given index in the res list to the res2 list:
for x in res:
  res2.append(reversed_alphabets[x])

#Convert the res2 list to string:
n = "".join(res2)

#print it:
print(n)

Python 粉丝会注意到，任何执行

range(len(x))

的 for 循环几乎总是可以通过迭代 x:

来做得更好

for x in getString:
  if x in alphabets:
    m = alphabets.index(x)
    res.append(m)