在特殊字符前面添加空格

Question

如果这些特殊字符粘在一个单词上，如何在Python中创建RE以在这些特殊字符前面添加空格？,?!

这是输入字符串：

myString= 'I like him, but is he good? Maybe he is good , smart, and strong.'

所需的输出（如果特殊字符不粘在单词上，则不会被修改）：

modifiedString= 'I like him , but is he good ? Maybe he is good , smart , and strong.'

我已经尝试过这个回复：

modifiedString= re.sub('\w,' , ' ,' ,myString)

但它给出了错误的结果。它删除逗号之前的最后一个字符，这是结果示例：

modifiedString = 'I like hi , but is he good? Maybe he is goo , smar , and strong.'

有什么建议可以解决这个问题吗？

Answer 1

您可以使用re.sub：

>>> import re
>>> myString= 'I like him, but is he good? Maybe he is good , smart, and strong.'
>>> re.sub('(?<=\w)([!?,])', r' \1', myString)
'I like him , but is he good ? Maybe he is good , smart , and strong.'
>>>

(?<=\w)是匹配单词字符的回溯断言。

([!?,])是与字符集匹配的捕获组[!?,]（您可以在方括号内添加要匹配的更多字符）。

\1指的是 捕获的文本([!?,])。