regex module

Meta Characters
[] A set of characters
\ Signals a special sequence(can also be used to escape special characters)
. Any character(except newline character)
^ Starts with
$ Ends with
* Zero or more occurrences
+ One or more occurrences
{} Exactly the specified number of occurrences
| Either or
() Capture and group
Special Sequences
\A Returns a match if the specified characters are at the beginning of the string
\b Returns a match where the specified characters are at the beginning or at the end of a word r"ain\b"
\B Returns a match where the specified characters are present, but NOT at the beginning ( or at the end) of a word

\d Returns a match where the string contains digits(numbers from 0-9)
\D Returns a match where the string DOES NOT contain digits
\s Returns a match where the string contains a white space character
\S Returns a match where the string DOES NOT contain a white space character
\w Returns a match where the string contains any word characters(characters from a to Z, digits from 0-9, and the underscore _ character)
\W Returns a match where the string DOES NOT contain any word characters
\Z Returns a match if the specified characters are at the end of the string