使用正则表达式从字符串中提取日期和时间 [英] Extract Date and Time from a String Using Regex

问题描述

我正在研究一个正则表达式，它接受所有可能的日期和时间格式以从句子中提取它们.

I am working on a regex that accepts all possible formats of date and time to extract them from a sentence.

这是我的正则表达式:

@"(?:(?:31(\/|-|\.)(?:0?[13578]|1[02]|(?:Jan|Mar|May|Jul|Aug|Oct|Dec)))\1|(?:(?:1|30)(\/|-|\.)(?:0?[1,3-9]|1[0-2]|(?:Jan|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec))\2))(?:(?:1[6-9]|[2-9]\d)?\d{2})$|^(?:29(\/|-|\.)(?:0?2|(?:Feb))\3(?:(?:(?:1[6-9]|[2-9]\d)?(?:0[48]|[2468][048]|[13579][26])|(?:(?:16|[2468][048]|[3579][26])00))))$|^(?:0?[1-9]|1\d|2[0-8])(\/|-|\.)(?:(?:0?[1-9]|(?:Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep))|(?:1[0-2]|(?:Oct|Nov|Dec)))\4(?:(?:1[6-9]|[2-9]\d)?\d{2})(?:[\D]*)(?<time>\d{1,2}\:\d{2}\s(?:A|P)M)";

目前，正则表达式在提取句子中任何位置的时间时效果很好，但只有在句首时才提取日期.此外，如果句子中有第二个日期，则正则表达式不会确认它，但如果在它与日期旁边的文本匹配之后直接有文本.

Currently, the regex works perfectly when extracting time at any position in the sentence but extracts the date only if it is at the beginning of a sentence. Also, if there is a second date in the sentence the regex does not acknowledge it but if there is text directly after it matches the text alongside the date.

例如:

Meet me on 31/07/2019 at 3:00 PM to celebrate and then the meeting will be on 03/08/2019 at 12:00 PM.

正则表达式应该匹配:

1) 31/07/2019

2) 3:00 PM

3) 03/08/2019

4) 12:00 PM

注意:应从句子的任何部分(开头、中间、结尾)中提取预期输出

Note: The expected output should be extracted from any part of the sentence (Beginning, Middle, End)

推荐答案

\D* + 时间模式之前的正则表达式部分匹配各种类型的日期，并且必须在添加任何其他模式之前进行分组跟随.即，(?DATE1_PATTERN|DATE2_PATTERN|DATEn_PATTERN)\D*(?TIME_PATTERN).

Your regex part before the \D* + time pattern matches various types of dates, and must be grouped before adding any other pattern to follow. That is, (?<date>DATE1_PATTERN|DATE2_PATTERN|DATEn_PATTERN)\D*(?<time>TIME_PATTERN).

然后，只需匹配和访问命名组:

Then, just match and access named groups:

var s = "Meet me on 31/07/2019 at 3:00 PM to celebrate and then the meeting will be on 03/08/2019 at 12:00 PM.";
var pattern = @"(?<date>(?:(?:31([-/.])(?:0?[13578]|1[02]|(?:Jan|Mar|May|Jul|Aug|Oct|Dec)))\1|(?:(?:1|30)([-/.])(?:0?[13-9]|1[0-2]|(?:Jan|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec))\2))(?:(?:1[6-9]|[2-9]\d)?\d{2})|(?:29([-/.])(?:0?2|Feb)\3(?:(?:(?:1[6-9]|[2-9]\d)?(?:0[48]|[2468][048]|[13579][26])|(?:(?:16|[2468][048]|[3579][26])00))))|(?:0?[1-9]|1\d|2[0-8])([-/.])(?:(?:0?[1-9]|(?:Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep))|(?:1[0-2]|(?:Oct|Nov|Dec)))\4(?:(?:1[6-9]|[2-9]\d)?\d{2}))\D*(?<time>\d{1,2}:\d{2}\s[AP]M)";
var result = Regex.Matches(s, pattern);
foreach (Match m in result) {
    Console.WriteLine(m.Groups["date"].Value);
    Console.WriteLine(m.Groups["time"].Value);
}

参见 C# 演示，输出:

31/07/2019
3:00 PM
03/08/2019
12:00 PM

这是.NET 正则表达式小提琴.

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