regex

问题 Is it possible to extract a max length of an allowed string from a regex pattern once it has been loaded into a C# Regex object? If I have a Regex string defined as @"^[A-Z0-9]{0,20}$" , I could use string manipulation to get the maximum allowed length of 20 . However is there a way I can get that more easily, for instance via a Regex object as follows: var r = new Regex(@"^[A-Z0-9]{0,20}$"); // var max = r.MaxLength; Update To set some context, I have an Asp.Net MVC 5 application in which we

问题 I have a list of words and a string and would like to get back a list of words from the original list which are found in the string. Ex: import re lof_terms = ['car', 'car manufacturer', 'popular'] str_content = 'This is a very popular car manufacturer.' pattern = re.compile(r"(?=(\b" + r"\b|".join(map(re.escape, lof_terms)) + r"\b))") found_terms = re.findall(pattern, str_content) This will only return ['car', 'popular']. It fails to catch 'car manufacturer'. However it will catch it if I

问题 I have searched high and low and am really struggling to find the appropriate REGEX that would help me retrieve what I want. Assume I have the following query string: SELECT col, col2 AS c2, col3, col * col2 calc FROM... I want a REGEX that will pull out everything between commas where there is a space or an "AS" that proceeds a column alias. It should also exclude the SELECT and FROM. With the example above, I would want the following matches: col2 AS c2 col * col2 calc Essentially, this

问题 I have searched high and low and am really struggling to find the appropriate REGEX that would help me retrieve what I want. Assume I have the following query string: SELECT col, col2 AS c2, col3, col * col2 calc FROM... I want a REGEX that will pull out everything between commas where there is a space or an "AS" that proceeds a column alias. It should also exclude the SELECT and FROM. With the example above, I would want the following matches: col2 AS c2 col * col2 calc Essentially, this

问题 when i retrieve data from our website url, that return this output in one of rest api fields and i try to found if tracks is contained i get url from that which in this below tracks source is that i need to get String test = """ <div class=\"wp-playlist wp-audio-playlist wp-playlist-light\">\n <div class=\"wp-playlist-current-item\"></div>\n <p>\t\t<audio controls=\"controls\" preload=\"none\" width=\"\n\t\t\t\t1118\t\"\n\t\t> </audio></p>\n<div class=\"wp-playlist-next\"></div>\n<div class=\

问题 when i retrieve data from our website url, that return this output in one of rest api fields and i try to found if tracks is contained i get url from that which in this below tracks source is that i need to get String test = """ <div class=\"wp-playlist wp-audio-playlist wp-playlist-light\">\n <div class=\"wp-playlist-current-item\"></div>\n <p>\t\t<audio controls=\"controls\" preload=\"none\" width=\"\n\t\t\t\t1118\t\"\n\t\t> </audio></p>\n<div class=\"wp-playlist-next\"></div>\n<div class=\

问题 Is it possible to match the following in a single regular expression to get the first word, and then a list of the numbers? this 10 12 3 44 5 66 7 8 # should return "this", "10", "12", ... another 1 2 3 # should return "another", "1", "2", "3" EDIT1: My actual data is not this simple, the digits are actually more complex patterns, but for illustration purposes, I've reduced the problem to simple digits, so I do require a regex answer. The numbers are unknown in length on each line, but all

问题 when I use negative lookahead on this string 1pt 22px 3em 4px like this /\d+(?!px)/g i get this result (1, 2, 3) and I want all of the 22px to be discarded but I don't know how should I do that 回答1: Add a digit pattern to the lookahead: \d+(?!\d|px) See the regex demo This way, you will not allow a digit to match after 1 or more digits are already matched. Another way is to use an atomic group work around like (?=(\d+))\1(?!px) See the regex demo. Here, (?=(\d+)) captures one or more digits

问题 when I use negative lookahead on this string 1pt 22px 3em 4px like this /\d+(?!px)/g i get this result (1, 2, 3) and I want all of the 22px to be discarded but I don't know how should I do that 回答1: Add a digit pattern to the lookahead: \d+(?!\d|px) See the regex demo This way, you will not allow a digit to match after 1 or more digits are already matched. Another way is to use an atomic group work around like (?=(\d+))\1(?!px) See the regex demo. Here, (?=(\d+)) captures one or more digits

问题 when I use negative lookahead on this string 1pt 22px 3em 4px like this /\d+(?!px)/g i get this result (1, 2, 3) and I want all of the 22px to be discarded but I don't know how should I do that 回答1: Add a digit pattern to the lookahead: \d+(?!\d|px) See the regex demo This way, you will not allow a digit to match after 1 or more digits are already matched. Another way is to use an atomic group work around like (?=(\d+))\1(?!px) See the regex demo. Here, (?=(\d+)) captures one or more digits