如何使用正則表達式在單詞邊界處拆分？

Question

我正在嘗試這樣做：

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

結果是

[u'How are you?']

我想要[u'How', u'are', u'you', u'?']東西。 如何做到這一點？

Answer 1

不幸的是，Python無法通過空字符串進行拆分。

要解決這個問題，您需要使用findall而不是split 。

實際上\\b只是意味着詞邊界。

它相當於(?<=\\w)(?=\\W)|(?<=\\W)(?=\\w) 。

這意味着，以下代碼將起作用：

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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輸出：

['How', 'are', 'you', '?']

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Ideone演示

Regex101演示

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正則表達式說明：

"[\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

Answer 3

這是我在單詞邊界上split的方法：

re.split(r"\b\W\b", "How are you?") # Reprocess list to split on special characters.
# Result: ['How', 'are', 'you?']

並在單詞邊界上使用findall

re.findall(r"\b\w+\b", "How are you?")
# Result: ['How', 'are', 'you']