The regexes in these recipes are all pretty straightforward, but hopefully this gives an example of the depth you can expect from the book. Both are followed by a question mark, which makes them optional.
For more than 100 detailed regular expression recipes that include equal coverage for eight programming languages (C#, Java, Java Script, Perl, PHP, Python, Ruby, and VB. We’ll explain more about the question mark after discussing the other types of tokens in this regular expression.
The following layout breaks the regular expression into its individual parts, omitting the redundant groups of digits: ^ # Assert position at the beginning of the string. Any quantifier that allows something to be repeated zero times effectively makes that element optional.
Howdy I've been searching for a decent phone number regular expression validation and it turns out a lot harder to dig one up than I expected.
(Guido van Rossum) The aim of this chapter of our Python tutorial is to present a detailed led and descriptive introduction into regular expressions.