如何使用正则表达式在单词边界处拆分？

Question

我正在努力做到：

import re
sentence = "How are you?"
print(re.split(r'\b', sentence))

结果是

^{pr2}$

我想要一些类似[u'How', u'are', u'you', u'?']的东西。如何做到这一点？在

Answer 1

不幸的是，Python不能被空字符串分割。在

要解决这个问题，您需要使用findall，而不是split。在

实际上\b只是单词边界的意思。在

它相当于(?<=\w)(?=\W)|(?<=\W)(?=\w)。在

这意味着，以下代码将起作用：

import re
sentence = "How are you?"
print(re.findall(r'\w+|\W+', sentence))

Answer 2

import re
split = re.findall(r"[\w']+|[.,!?;]", "How are you?")
print(split)

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输出：

^{pr2}$

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Ideone Demo

Regex101 Demo

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正则表达式说明：

"[\w']+|[.,!?;]"

    1st Alternative: [\w']+
        [\w']+ match a single character present in the list below
            Quantifier: + Between one and unlimited times, as many times as possible, giving back as needed [greedy]
            \w match any word character [a-zA-Z0-9_]
            ' the literal character '
    2nd Alternative: [.,!?;]
        [.,!?;] match a single character present in the list below
            .,!?; a single character in the list .,!?; literally