I have this regex that uses forward and backward look-aheads: import re re.compile("<!inc\((?=.*?\)!>)|(?<=<!inc\(.*?)\)!>") I'm trying to port it from C# to Python but keep getti...

I am looking to match a string "Order By XXX" where XXX can be any letter, number, period, comma, space or square bracket. However, I would only like to match this if it is not surrounded by parent...

I have this pattern written ^.*\.(?!jpg$|png$).+$ However there is a problem - this pattern matches file.name.jpg (2 dots) It works correctly (does not match) on filename.jpg. I am trying to f...

I have user input where some tags are allowed inside square brackets. I've already wrote the regex pattern to find and validate what's inside the brackets. In user input field opening-bracket coul...

Is there a way to do negative and positive lookbehind in VBA regex? I want to not match if the string starts with "A", so I am currently doing ^A at the start of the pattern, then removing the fir...

Making an argument parser. I want to split a string into an array where the delimiter is ", " except when preceded by "|". That means string "foo, ba|, r, arg" should result in `["foo", "ba|, r...

I need to emulate the behavior of \b at the start of a string, where I'm adding additional characters to the set that count as a word boundary. Right now I'm using something like: "(?<=\\W|\\p{...

I am doing some replaces in some huge SSIS packages to reflect changes in table- and column names. Some of the tabels have columnnames witch are identical to the tablenames and I need to match the ...

How can I use lookbehind in a C# Regex in order to skip matches of repeated prefix patterns? Example - I'm trying to have the expression match all the b characters following any number of a charac...

I want to parse the 2 digits in the middle from a date in dd/mm/yy format but also allowing single digits for day and month. This is what I came up with: (?<=^[\d]{1,2}\/)[\d]{1,2} I want a ...

I have the following regex in a C# program, and have difficulties understanding it: (?<=#)[^#]+(?=#) I'll break it down to what I think I understood: (?<=#) a group, matching a hash. what...

Can you use backreferences in a lookbehind? Let's say I want to split wherever behind me a character is repeated twice. String REGEX1 = "(?<=(.)\\1)"; // DOESN'T WORK! String REGEX2 = "(?&lt...

In the "Advanced Regular Expresssion" chapter in Mastering Perl, I have a broken example for which I can't figure out a nice fix. The example is perhaps trying to be too clever for its own good, bu...

I use (?<!value=\")##(.*)## to match string like ##MyString## that's not in the form of: <input type="text" value="##MyString##"> This works for the above form, but not for this: (I...