python - 根据正则表达式模式拆分字符串

Question

我有一条消息正在尝试拆分。

import re

message = "Aug 10, 17:04 UTCThis is update 1.Aug 10, 15:56 UTCThis is update 2.Aug 10, 15:55 UTCThis is update 3."

split_message = re.split(r'[a-zA-Z]{3} (0[1-9]|[1-2][0-9]|3[0-1]), ([0-1]?[0-9]|2[0-3]):[0-5][0-9] UTC', message)

print(split_message)

预期输出:

["This is update 1", "This is update 2", "This is update 3"]

实际输出:

['', '10', '17', "This is update 1", '10', '15',  "This is update 2", '10', '15', "This is update 3"]

不确定我错过了什么。

Answer 1

您正在使用“捕获组”，这就是为什么它们的内容也是结果数组的一部分的原因。您需要使用非捕获组(以 ?: 开头):

import re

message = "Aug 10, 17:04 UTCThis is update 1.Aug 10, 15:56 UTCThis is update 2.Aug 10, 15:55 UTCThis is update 3."

split_message = re.split(r"[a-zA-Z]{3} (?:0[1-9]|[1-2][0-9]|3[0-1]), (?:[0-1]?[0-9]|2[0-3]):[0-5][0-9] UTC", message)

print(split_message)

然而，您总是首先得到一个空条目，因为空字符串位于您的第一个拆分模式前面:

['', 'This is update 1.', 'This is update 2.', 'This is update 3.']

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如 docs 中所述:

If capturing parentheses are used in pattern, then the text of all groups in the pattern are also returned as part of the resulting list.