python - 如何在python中替换列表中的字符

Question

我想在 python 中编写一个代码，它将每个小写字母字符替换为“a”，每个大写字母替换为“A”，每个数字替换为 0。我编写了代码，但它导致了 x 的错误不在列表中，代码在下面

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']