Question

我想在python中编写一个代码，用＆＃34; a＆＃34;替换每个小写字母。，每个大写字母都带有＆＃34; A＆＃34;并且每个数字都为0.我编写代码但导致错误 x不在列表中，代码低于

tokens = ["apple","banana","Orange", "pineApple", "10nuts"]
for token in tokens:
    for ch in token:
        if ch.islower():
            loc = tokens.index(ch)
            tokens.remove(ch)
            tokens.insert(loc,'a');
        elif ch.isupper():
            loc = tokens.index(ch)
            tokens.remove(ch)
            tokens.insert(loc,'A');
        elif ch.isdigit():
            loc = tokens.index(ch)
            tokens.remove(ch)
            tokens.insert(loc,'0');
for t in tokens:
    print t

Answer 1

使用regular expressions：

from re import sub

tokens = ["apple","banana","Orange", "pineApple", "10nuts"]

for i, token in enumerate(tokens):
    token = sub(r'[A-Z]', 'A', token)
    token = sub(r'[a-z]', 'a', token)
    token = sub(r'\d', '0', token)
    tokens[i] = token

print tokens
## Output: ['aaaaa', 'aaaaaa', 'Aaaaaa', 'aaaaAaaaa', '00aaaa']

Answer 2

您应该使用正则表达式来执行此任务：

import re

tokens = ["apple","banana","Orange", "pineApple", "10nuts"]

upper = re.compile(r"[A-Z]")
lower = re.compile(r"[a-z]")
number = re.compile(r"[0-9]")

for token in tokens:
    token = re.sub(upper,'A',token)
    token = re.sub(lower,'a',token)
    token = re.sub(number,'0',token)
    print token

变量upper，lower和number是预编译的正则表达式，因为你在循环中使用它们，这样会更快。

您还可以将循环缩短为三行：

for token in tokens:
    token = re.sub(upper,'A',re.sub(lower,'a',re.sub(number,'0',token)))
    print token

希望这有帮助

编辑：使用单行代码从上面取代我的代码，但是使用了pzp1997建议的枚举循环：

import re

tokens = ["apple","banana","Orange", "pineApple", "10nuts"]

upper = re.compile(r"[A-Z]")
lower = re.compile(r"[a-z]")
number = re.compile(r"[0-9]")

for i, token in enumerate(tokens):
    tokens[i] = re.sub(upper,'A',re.sub(lower,'a',re.sub(number,'0',token)))

print tokens

如何在python中替换列表中的字符

2 个答案: