Regex match letters and numbers. Text. Description. Dec 25, 2012 · You can try something like this: -. \d is a digit (assuming you mean this with "real number") ^ is the start of the string. Anirudha. Text); Oct 7, 2013 · EDIT: \d is not necessary. g. NET, Rust. myRegularExpression. You can define a regular expression as follows, Regex myRegularExpression = new Regex(" \b^[a-zA-Z0-9]+$\b"); be sure to include System. So, test for this :-. Dim myMatches As Variant. Any help would be appreciated! This would be for validating usernames for my website. Nov 11, 2011 · 0. Match. The match made with this part of the pattern is remembered for later use, as described in Using groups . Regex uppercase and numbers. Thus: - matches a hyphen. 09 ####. I need to modify it to require at least one number or letter somewhere in the string. Set GetRIs = New Collection. @"^\w+$". Result: ( * indicates a match) * AB1234. If "number followed by a period" means "string of digits 0-9 followed by a period", then this is a great answer (but I don't see anything in the question to justify the ^ and $ anchors). Here is an example: var alphanumeric = "someStringHere"; May 19, 2015 · I'm currently using this regex ^[A-Z0-9 _]*$ to accept letters, numbers, spaces and underscores. 2. Jan 21, 2016 · Use a simple character class wrapped with letter chars: ^[a-zA-Z]([\w -]*[a-zA-Z])?$ This matches input that starts and ends with a letter, including just a single letter. This will match any string which starts with a capital letter, followed by 3 digits, a hypen and 3 digits. "The following regex matches alphanumeric characters and underscore" doesn't limit it to Latin letters. Oct 11, 2013 · 1. /^([a-zA-Z0-9]+)$/. In general, you can put a period literal in a regex by escaping it with a backslash. ## the numbers could be anything but the digits are always 4 Apr 5, 2011 · 0. Your second alternative only has $ anchor, so it just checks thatthe end of the input is 4 digits. Match regex letters and number. *") 1st line is checking that string is not only letter and. *') then "True" else "False" endif. Dim myRegExp As RegExp. Later on, I will introduce some regex challenges that you'll solve using Python. This match any string which starts with a capital letter, followed by 3 digits, a hypen and one or Sep 2, 2011 · The pattern you're looking for, that matches only those strings with numbers, . The problem with this: ^[a-zA-Z]*[a-zA-Z0-9]+$ is that you are using the * operator, which denotes 0 or more repetitions. Regular expressions are the default pattern engine in stringr. Each group is four letters. Match returns the first Match only. Dec 3, 2008 · "I would like to have a regular expression that checks if a string contains only upper and lowercase letters, numbers, and underscores" doesn't limit it to Latin letters. I. [A-Z][0-9]{3}-[0-9]+. I want to match like 232424-42-2455. * @return s, if it passes the above test. May 7, 2011 · The regex is built in order that it can detect the numbers expressed in scientific notation 2E10 or even 5,22,454. search. it will match. This is an interesting case. isMatch(myTextBox. (?<numbers>[0-9]+) Match a single character present in the list below. Do so by checking for anything that matches the complement of the valid alphanumeric string. Jan 28, 2014 · You want to match individual groups of letters / numbers in brackets, and the current regex will match only a single string of one or more such groups. The re module offers a set of functions that allows us to search a string for a match: Function. When expressed that way you can translate the requirement to a regex directly. \d is a digit (0-9) {4} says there must be exactly 4 of the previously mentioned group ( \d) You did not specify what is allowed to follow the four digits. How can I modify to achieve what I want really want? I believe \w also includes underscore. Use square brackets [] to match any characters in a set. ^L[0-9]{8}$. (regex) and group(1) you can use. Optionally follow that from zero to 7 times by ## and a repetition of the first match. First formula is the original. four more numbers. 00. 1-4 number or 1-4 letter combo (required). Regex, short for regular expression, is a sequence of characters that defines a search pattern. !? ]*$/' It should allow a simple sentence such as "HI my name is John! Jul 14, 2011 · There are four groups of letters, separated by dashes. Jan 17, 2017 · Or you can have a fixed number of nestings (say a person can't nest brackets inside brackets more than 3 times). The + quantifier means to match one or more of the preceding pattern . RegularExpressions; string value = "4 AND 5" ; // Step 1: get first match. For example, the pattern [abc] will only match a single a, b, or c letter and nothing else. Test String. Mar 16, 2020 · In other words, you wish to match a string that contains only letters and digits and contains at least one letter. Try this. Returns a Match object if there is a match anywhere in the string. or G followed by 4 numbers followed by a single letter A-Z. Explanation: \b is a word boundary, a zero length match. [RL] is a character class, it matches either R or L. [abc-] matches a, b, c or a hyphen. You don't need to escape the / and . If you’re not using raw strings, then Python will convert the \b to a backspace, and your RE won’t match as you expect it to. It just allow with one hyphen with single digit like 3-3-3. Three problems here: Just use String. e any number from 0 to 9 the regex is simple /[0-9]/ Regex for 1 to 9 Apr 21, 2021 · I'd like to match a range of digits and characters to replace them with sed; a Perl-like regex I would tend to write would be: [\d-_]+ to match, for example, digits and dashes and underscores. It appears that regex_match and regex_replace act in slightly different ways. ] or [,] You can also state a selection between possible values as such. answered Oct 11, 2013 at 3:19. How to write regex that match start with a letter, can contain letters, numbers, hyphens and 1 underscore? 3. [. 32. A better regex that would match only up to the closing bracket would be. " Or so say the docs (EDIT: Corrected formatting) If we are matching phone numbers for example, we don't want to validate the letters " (abc) def-ghij" as being a valid number! There is a method for matching specific characters using regular expressions, by defining them inside square brackets. 2093. * @throws IllegalArgumentException if it does not. Jun 29, 2015 · Instead of checking for a valid alphanumeric string, you can achieve this indirectly by checking the string for any invalid characters. "letter" can be any letter Unicode or Latin-1. Feb 14, 2010 · 13. The * means that (only) 0 or more numbers or dashes should be there (use + instead for 1 or more). The last example includes parentheses, which are used as a memory device. $ is the end of the string. Use \s to match any single whitespace character. compile() a string, and your current regular expression will only match a single character, try changing it to the following: import re pattern = re. You’ll learn more about what each part of a regex means in a minute. The above 3 work except for the 4th condition. 212k 45 413 529. This works. though, just the -. In this one, the user is presented with the number keyboard so some characters are not important as such. i @Anirudh I use the answer but if a put "La1234567" marks right only the first letter could be letter and needs to be 'L', any May 12, 2010 · # match 0 or 1 '_' [a-z0-9]+ # match a letter or number, 1 or more times )* # end non-capture group, match whole group 0 or more times $ # match end of string /i # case insensitive flag The non-capture group takes care of a) not allowing two _ 's (it forces at least one letter or number per group) and b) only allowing the last char to be a Jun 10, 2022 · python regular expression matching either all uppercase letter and number or just numbers. Detailed match information will be displayed here automatically. And you just need to concatenate the pieces together, so in the case where you want to represent a 1 or 2 digit number followed by either a comma Sep 5, 2019 · You can use this: Regex regex = new Regex(@"^BR\d{4}"); ^ defines the start of the string (so there should be no other characters before BR) BR matches - well - BR. Sep 8, 2015 · match any character 0-9 starting at the second spot ( [0-9]) the preceding pattern mentioned in step 3 of [0-9] must exist exactly 7 times ( {7}) When you put {8} as per your original question, you'll assume a string length total of 9: the first character being alphabetic case insensitive and the remaining 8 characters being numeric. Your regex will match anything that contains a number, you want to use anchors to match the whole string and then match one or more numbers: regex = new Regex("^[0-9]+$"); The ^ will anchor the beginning of the string, the $ will anchor the end of the string, and the + will match one or more of what precedes it (a number in this case Jan 2, 2024 · A regular expression pattern is composed of simple characters, such as /abc/, or a combination of simple and special characters, such as /ab*c/ or /Chapter (\d+)\. Workflow: Regex Match for Number Range. Jul 25, 2014 · The {3} means that, match only three times. 1. split. AAA999 all 6 are required for this to be valid. How do you require a letter? How do you require the string to only contain certain characters? – Nov 21, 2014 · PHP only letters, numbers, spaces remaining in string. Rohit Jain. 6k 7 70 89. a-zA-Z\d after that means "period, alphabets and numbers". Step 2 NextMatch returns another Match object—it does not modify the current one. The regex you are using is pretty good. Sep 16, 2016 · alphaNumeric = new Regex("^[a-zA-Z0-9]*$"); for my custom TextBox. An example of the expression is shown here . A Regular Expression – or regex for short– is a syntax that allows you to match strings with specific patterns. Apr 25, 2014 · Match at least one string that begins with two capital letters that is followed by 4 decimal digits. Think of it as a suped-up text search shortcut, but a regular expression adds the ability to use quantifiers, pattern collections, special characters, and capture groups to create extremely advanced search Feb 19, 2023 · To match a string of unknown characters and digits and unknown numbers as one string, you can use the regular expression /[\w\d]+/. It can be alphanumeric AB12354KFJKL, or dates 11/01/2014, or numbers with hyphens in the middle, 123-489-568, or just plain normal numbers 123456789 - but it can't match anything without numbers. *\W. " I have tried this regex with no success and I am currently searching for others to try. So I tried to do this: 1. (Note that the trailing . \([0-9a-zA-Z^\)]+\) Problem with regexes is that they can be difficult to maintain/understand. 0. Use \d to match any single digit. Can you explain for the number one. Regex. 1234, or 1231231234. We assign a variable to it. match(some_string) . The syntax of the function is as follows: RegEx_Match(My_Text,Text_Pattern,IfMatched,IFUnMatched,CaseMatch) This function will have 5 arguments, of which 3 are optional. I have just copied the name Regex and pasted it here but removed 0-9 in order to be able to input the numbers. Alternatively you can allow for infinite nesting and use the regex just to make sure you have equal number of opening and closing brackets and afterwards add some code that checks the correct balancing if the regex matched. {8} is a qauntifier which would match 8 digits. This is the VBA code I'm using get the matches. [0-9] + matches the previous token between one and unlimited times, as many times as possible, giving back as needed (greedy) 0-9 matches a single character in the range between 0 (index 48) and 9 (index 57) (case sensitive) Nov 10, 2023 · Step 1 We call Regex. It matches the newlines as well because, \D anything but a digit. 12E-00. The references will always be wrapped in brackets, and there will always be a colon between the two. ^\d{4}\/\d{2}\/\d{4}$. Mar 9, 2016 · I'm using RegExBuddy to try and figure this out. If you want it to start with a letter, just use this: ^[a-zA-Z][a-zA-Z0-9]*$. not a punctuation symbol. ,] means either a dot or a comma symbol. Depending on context, "4e-3" is a number, as is "0xdeadbeef", and "3/4". Now in your. \p{Nd} or \p{Decimal_Digit_Number}: a digit zero through nine in any script except ideographic scripts. answered Dec 25, 2012 at 13:04. Jul 21, 2015 · Thus, the regular expression ^\p{Lu}\p{Ll}+( \p{Lu}\p{Ll}+)*$ will match an upper case letter followed by one or more lower case letters, followed by 0 or more other names, seperated by spaces. The . Then one or more digits at the end. Viewed 9k times Part of PHP Collective RegEx Functions. Aug 5, 2014 · I have a requirement of a regular expression. Since, a newline is not a digit, even that also has got matched. So this way the string will have both letters and numbers . Use \w to match any single alphanumeric character: 0-9, a-z, A-Z, and _ (underscore). Apr 3, 2012 · You need to provide re. Feb 24, 2022 · Heyho, I'm pretty new to using regex, and I can't seem to find the right regex to match a pattern like this: 1000. In case the first letter must be either 'R' or 'L', then this will be better: `\b[RL][0-9RL]*\b`. ^([0-9]+-)*[0-9]+$. [A-Za-z]+ matches any lower/upper case letter more than once. This is true. Could someone please assist? e. Your first alternative that matches letters only has the ^ anchor, so it just checks that the input begins with 3 letters or 2 letters separated by hyphen. – kennytm. Nov 3, 2011 · i am having a problem creating a regular expression that will validate if the textbox has a three letters in the beginning and three numbers at the end e. *[A-D]. three upper-case letters followed by a hyphen. of valid entries would be: G2 G12 G123 G1234 G12345 G1234A Thanks Feb 2, 2017 · The group of a letter followed by any number of any characters is repeated four times, so this pattern matches if and only if at least four letters appear in the string. Jun 23, 2017 · [0-9]% a string that has a character from 0 to 9 before a % sign [^a-zA-Z] a string that has not a letter from a to z or from A to Z. ^ marks the beginning of string/line and $ marks the end of string/line. Jun 20, 2011 · 4. RegEx to make sure that the string contains at least one uppercase and lowercase letter but also may include numbers and special characters 1 Regex: Validate if a string is [a-zA-Z0-9] only, 8+ chars, has at least one of lowercase, uppercase, digits Jan 11, 2017 · I need a regular expression to match any word (by word I mean anything between full spaces) that contains numbers. Regex pattern - matching capital letters with combination of numbers and Apr 29, 2013 · \d matches a digit [a-zA-Z] matches a letter {3} is the quantifier that matches exactly 3 repetitions ^ Anchor to match the start of the string $ Anchor to match the end of the string I'm trying to parse a document that has reference numbers littered throughout it. mozilla. Global = True. org Dec 19, 2012 · How can I create a regex expression that will match only letters with numbers? I've tried something like (?&gt;[A-z]+)([a-z0-9]+). findall. Regular expression for letters, numbers and - _ 1. regex and group(0) Next thing is that \\w is already character class so you don't need to surround it with another [ ], because it will be similar to [[a-z]] which is same as [a-z]. a number. Could you provide me with a regex that filters the string so that it only contains English Apr 16, 2012 · All I want to do is, validate whether a string contains upper case letters and/or numbers. Usually a word boundary is used before and after number \b or ^ $ characters are used for start or end of string. Problem is, when a space is inserted, it still counts it as a May 4, 2023 · This regular expression pattern is used to match any string that consists of only letters, numbers, and whitespace characters. symbol you would use: \, or \. compile(r'^[A-Z\d]+$') Now you can test strings to see if the match this pattern by using pattern. powerShell and regular expression. Regex to find numbers and letters. You need to put both anchors in both alternatives. Regex to match only few letters and numbers. 2[0-4][0-9] matches 200 through 249. Example 1 regex: a[bcd]c. e. It takes a text or reference to a May 18, 2023 · Regex in C# defines a regular expression in C#. Text text text {4:2} more incredible text {4:3} much later on {222:115} and yet some more text. Regex for range 0-9. Example 2 regex: a[0-7]c. The 3rd one expands the expression to match the entire field. will only allow a single space between words and no leading or trailing spaces. An easier solution would be to retain your existing regex, then create two new regexes to test for your "at least one alphabetic" and "at least one numeric". Ask Question Asked 14 years ago. There are a few tools available to users who want to verify and test their regex syntax. This pattern would match that: ^[\dA-F]{4}-[\dA-F]{4}-[\dA-F]{4}-[\dA-F]{4}$. The _ here is unnecessary in Python 3 as the \w will match "most characters that can be part of a word in any language, as well as numbers and the underscore. if it is a single word you are matching without spaces, with both numbers and letters, it can be assumed they touch somewhere - so if it matches letter then number or number then letter we have a match - so: ([a-zA-Z][0-9]|[0-9][a-zA-Z]) Edit: where there may be spaces then you can use lookahead assertions like this. How can I create a regex expression that will match only letters and numbers, and one space between each word? Good Examples: Amazing Hello World I am 500 years old Bad Examples: Hello world I am 500 years old. Now this will match 0 or more repetition of some digits followed by a hyphen. [0-9] is a range within the character class, it Apr 14, 2022 · By Corbin Crutchley. So when I press a key it only adds to the TextBox's string if it is: an English letter. Only if it’s in a character class and between two other characters does it take a special meaning. regex not working for php form validation. May 5, 2015 · Regular expression to match letters, numbers, and certain symbols. [\D] excludes there being digits after the letters, thus avoiding matching stuff like chromecar_CM123. So it'll match all characters which are not period, alphabets and numbers, then remove them. Aug 24, 2018 · This works for the Name RegExp. Jul 1, 2019 · if REGEX_Match([TEST],'. matches() - if the API is there, use it; In java "matches" means "matches the entire input", which IMHO is counter-intuitive, so let your method's API reflect that by letting callers think about matching part of the input as your example suggests Then if you want to add a , or a . Note: capital \D is the negation of the shorthand \d. Match(input, @"^[0-9-]*$"); The ^ means that the match should start at the beginning of the input, the $ that it should end at the end of the input. I am Chuck Norris First of all you don't need to add any group because entire match can be always accessed by group 0, so instead of. If an exponent is equal to zero , the number is modified so that there is no more exponent. Now about numeric ranges and their regular expressions code with meaning. The Regex class offers methods and properties to parse a large text to find patterns of characters. \w+ Match any word character [a-zA-Z0-9_] Quantifier: + Between one and unlimited times, as many times as possible, giving back as needed [greedy] Jul 16, 2012 · begins with only a letter or a numeric digit, and; only letter, space, dash, underscore and numeric digit are allowed; all ending spaces are stripped; In my regex, matcher('__') is considered valid. 3. Check if a string only contains numbers Match elements of a url Url Validation Regex | Regular Expression - Taha Match an email address Validate an ip address nginx test Match or Validate phone number Match html tag Find Substring within a string that begins and ends with paranthesis Blocking site with unblocked games Sep 8, 2014 · 33. Minimum 1 letter or number is required and the first number should not be 0. * Checks to see if the specified string has between 8 and 30 characters, has at least 2 digits, at least 2 letters, at least one special character, and no spaces. not a space. Dec 21, 2023 · Here, I have declared a public function named RegEx_Match. Oct 8, 2012 · Regex: Only 1 space but not at the start, no numbers/special characters, any string before or after space needs to have at least 2 alphabetic chars 1 How to match all word which starts with a space and character Find any character alphabetically between a specified upper-case letter and a specified lower-case letter: Try it » [A-Z] Find any character alphabetically between two upper-case letters. Use a character set: [a-zA-Z] matches one letter from A–Z in lowercase and uppercase. Jan 6, 2012 · Match match = Regex. Nov 1, 2010 · 236. ie [9-_] means "every char between 9 and _ inclusive. @Timay: The ^ means "any characters except". In this case the ^ is used as negation of the expression May 17, 2017 · Start with any letter. \w matches any "word character", defined as digits, letters, and underscores. Your regex should be. * @param s the String to be checked. The letters are hexadecimal digits. It's Unicode-aware so it'll match letters with umlauts and such (better than trying to roll your own character class like [A-Za-z0-9_] which would only match English letters). This will match a letter an any letters or numbers which might follow. In this article, you’ll learn how to use a Regex class in C#. The second, a replace using the same regex as the first. Set myRegExp = New RegExp. Here is: \b[a-zA-Z][0-9RL]*\b. [\p{L}\p{N}\p{Zs}]+: matches one or more characters from any of the following Unicode character classes: \p{L}: any kind of letter from any language. To match numeric range of 0-9 i. '/^[a-zA-Z0-9,. There is a bug in your regex: You have the hyphen in the middle of your characters, which makes it a character range. The ^ at the beginning means "match the beginning of the string here", and the Nov 29, 2014 · Regex: match letters WITH numbers only. That means when you use a pattern matching function with a bare string, it’s equivalent to wrapping it in a call to regex(): # The regular call: str_extract (fruit, "nana") # Is shorthand for str_extract (fruit, regex ("nana")) You will need to use regex() explicitly if you want Jul 10, 2014 · [-'0-9a-zÀ-ÿ] allows dash, apostrophe, digits, letters, and chars in a wide accented range, from which we need to subtract The + matches that one or more times The $ anchor asserts that we are at the end of the string Named Capture Group numbers. Dec 29, 2014 · Your regexp could look like this: _C[A-Za-z]+[\D], where: _C is the starting C you need. "^[a-zA-Z0-9_]+$" fails. Modified 9 years ago. 123. May 25, 2015 · Regex match string with at least one uppercase and at least one number from 0-9 0 Regex for at least one uppercase letter, one lowercase, one number OR special character May 7, 2023 · Therefore, with the above regex expression for finding phone numbers, it would identify a number in the format of 123-123-1234, 123. 138. Finally, 25[0-5] adds 250 till 255. As you can see, you need to split up the numeric range in ranges with the same number of digits, and each of those ranges The program states "Enter a regular expression which entered text must match (evaluated with preg_match, using s and i flags) for it to be valid. In this tutorial, we're going to cover regex basics with the help of this site. Thanks, May 10, 2022 · Jan 30, 2010 at 7:06. Feb 5, 2014 · I am having some difficulty with the following for a regular expression: G followed by 1-5 numbers. Regex tools. Jan 20, 2021 · 606. and then use the Regex to match it with your user-control as follows, eg : if your user-control is a textbox. The following list provides tools you can use to verify, create, and test regex May 19, 2021 · !REGEX_Match([Field1], "[[:alpha:]]+") AND !REGEX_Match([Field1], "\d+") AND !REGEX_Match([Field1], ". * of the fourth repeat of the pattern is mostly inconsequential, since it can match zero characters). But if the number of digits after - can be anything, then you can use. See full list on developer. Regex to matching strings Powershell. Public Function GetRIs(ByVal vstrInString As String) As Collection. [-] matches a hyphen. Dim myMatch As Variant. You can escape the hyphen inside a character class, but you don’t need to. The details of the arguments are as follows: My_Text= This argument is mandatory. myRegExp. The hyphen is usually a normal character in regular expressions. Sep 3, 2018 · Regular expression to capture each letter to the same capture group. AB1234x. Note that ^ and $ match the beginning and end of the string, which is important if you want to match the entire string and not check if the pattern Mar 12, 2024 · 28-JUL-2023. or you can use [. The anchors ^ and $ are important otherwise it will verify a string as OK with other stuff before or after. (abc) (def) (123) as a single group rather than three separate groups. \d*/ . Here, \w matches any word character (any letter, digit, or underscore) and \d matches any digit. Regular expression tester with syntax highlighting, explanation, cheat sheet for PHP/PCRE, Python, GO, JavaScript, Java, C#/. May 30, 2024 · Matching the three-digit numbers is a little more complicated, since we need to exclude numbers 256 through 999. Aug 1, 2023 · Some practical examples of using regex are batch file renaming, parsing logs, validating forms, making mass edits in a codebase, and recursive search. Two matches occur. 3rd line is checking that no special characters . But matcher('_') is not matched Mar 9, 2012 · \p{Lu} or \p{Uppercase_Letter}: an uppercase letter that has a lowercase variant. Let's break down the pattern: ^: asserts the start of the line. An explanation of your regex will be automatically generated as you type. Returns a list containing all matches. This call to Regex. Use a loop to traverse the string: /**. 1[0-9][0-9] takes care of 100 to 199. , -, and /: If you have a specific language you're looking to implement this I may be able to help you. So ABC1, 111 and ABC would be valid but abC1 would not be. Using a regex, we can express that format like this: [0-9] {2}-[A-Z] {3}-[0-9] {4} Note that the regular expression above expresses a pattern with: two numeric digits followed by a hyphen. Jul 2, 2022 · Match any specific character in a set. 0478, removing unnecessary zeros in the two parts of such numbers too. . RegularExpression. Here's the test I set up. answered Jun 20, 2011 at 9:13. Jul 14, 2011 · There are four groups of letters, separated by dashes. The regex should give the following result: 1234b --&gt; true 1234 Regular expression tester with syntax highlighting, explanation, cheat sheet for PHP/PCRE, Python, GO, JavaScript, Java, C#/. /[^a-z\d]/i. In Python’s string literals, \b is the backspace character, ASCII value 8. ^ and $ is the start and the end of the string May 7, 2019 · python regular expression matching either all uppercase letter and number or just numbers. Below is the explanation of the regular expression: ^ Assert position at start of the string. How to exclude special characters in a regular expression-2. Aug 27, 2015 · 2. contain numbers, 'R' and 'L'. 2nd line is checking that string is not only numbers and. [a-zA-Z]+ matches one or more letters and ^[a-zA-Z]+$ matches only strings that consist of one or more letters only ( ^ and $ mark the begin and end of a string respectively). If you want to match other letters than A–Z, you can either add them to the Apr 22, 2014 · So, at the beginning of 9999, [\D]* matches the empty string before 9999 and then [0-9]+ matches the digits 9999 and the rest of the string till the end will be matched by [\D]*. Regular expressions or commonly called as Regex or Regexp is technically a string (a combination of alphabets, numbers and special characters) of text which helps in extracting information from text by matching, searching and sorting. Try it » [123] Find one or many of the digits inside the brackets: Try it » [0-5] Find any digits between the two numbers: Try it » [0-9] Find any digits regex101: build, test, and debug regex. using System; using System. – 4 days ago · First, this is the worst collision between Python’s string literals and regular expression sequences. yw qv tw fl mx nt gm fy zg ys