Jan 17, 2013 · 34 (\w+)? and (\w*) both match the same (0..+inf word characters) However, there is a slight difference: In the first case, if this part of the regex matches "", the capturing group is …

Mar 27, 2014 · Email validation expression \w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)* allows empty spaces, but otherwise works perfectly. It does not fail the following email ...

Apr 25, 2013 · Modes 'r+', 'w+' and 'a+' open the file for updating (note that 'w+' truncates the file). Append 'b' to the mode to open the file in binary mode, on systems that differentiate between …

Oct 16, 2009 · Quick answer: ^[\w*]$ will match a string consisting of a single character, where that character is alphanumeric (letters, numbers) an underscore (_) or an asterisk (*). Details: …

If you split a string with a regex, you essentially tell where the string should be cut. This necessarily cuts away what you match with the regex. Which means if you split at \w, then …

Mar 29, 2016 · The sub-expression \w+ ( [.-]?\w+)* is used to match the username in the email, before the @ sign. It begins with at least one word character (a-z, A-Z, 0-9 and underscore), …

May 14, 2019 · I need a regex which will allow only A-Z, a-z, 0-9, the _ character, and dot (.) in the input. I tried: [A-Za-z0-9_.] But, it did not work. How can I fix it?

Oct 3, 2025 · In Python's built-in open function, what is the difference between the modes w, a, w+, a+, and r+? The documentation implies that these all allow writing to the file, and says that …

Jul 11, 2011 · I have this script uses regular expressions to check that a form field contains a valid email address.Please explain me from declare var emailfilter=/^\w+ [\+\.\w ...

Jun 2, 2009 · Email validation is hard. Pragmatically you can only assume it contains one @ and that there is at least one . following the @ somewhere but thats about it really if you want to …