正则表达式和 OR 运算符没有在 Python 中分组？
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Regex and the OR operator without grouping in Python?
提问by pedram
Here are the cases. I'm looking for the following pattern in a log file.
以下是案例。我正在日志文件中寻找以下模式。
All strings are in the form of AB_Nor CDE_N.
ABand CDEare fixed letters, followed by an underscore.
Ncan be either 2 or 3 numbers.
所有字符串都采用AB_Nor的形式CDE_N。
AB和CDE是固定字母，后跟下划线。
N可以是 2 或 3 个数字。
I tried (AB|CDE)_\d{2,3}but that returns a group. I can't do \w{2,3}\d{2,3}because it has to be either ABor CDEand not ACor FEG. Omitting the parentheses breaks too. I am sure the solution is simple but I'm new to python and regex and can't figure this out.
我试过了，(AB|CDE)_\d{2,3}但这会返回一个组。我不能这样做，\w{2,3}\d{2,3}因为它必须是ABorCDE和 not ACor FEG。省略括号也会中断。我确信解决方案很简单，但我是 python 和 regex 的新手，无法弄清楚。
采纳答案by mattmc3
A ?:inside a parenthesis in a regex makes it non-capturing. Like so: (?:AB|CDE)_\d{2,3}
?:正则表达式中括号内的A使其无法捕获。像这样：(?:AB|CDE)_\d{2,3}
See docs here: http://docs.python.org/3/library/re.htmlAbout a third of the way through it goes over the non-capturing syntax.
请参阅此处的文档：http: //docs.python.org/3/library/re.html大约三分之一的内容介绍了非捕获语法。
回答by BrenBarn
The non-capturing group syntax is (?:...). So do (?:AB|CDE)_\d{2,3}. This is documentedalong with everything else.
非捕获组语法是(?:...). 也一样(?:AB|CDE)_\d{2,3}。这与其他所有内容一起记录。
