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 …

Mar 29, 2016 · 1 /^(\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,3})+[,;]?[ ]?)+$/ this little beauty will allow you to enter one or more email addresses in a string, ending with a comma or semicolon, …

\w+? - [] Why doesn't any of the two first lines split the String on any character? The third expression \w*?, (question mark prevents greediness) works as I expected, splitting the String …

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: …

Nov 12, 2009 · 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?

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 …

Jun 3, 2010 · 4 Put w+ for writing the file, truncating if it exist, r+ to read the file, creating one if it don't exist but not writing (and returning null) or a+ for creating a new file or appending to a …

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 they open the fi...