Regex Examples

This repository contains examples of regular expressions in python

Specific matching rules:

\. is used for exactly matching the "." character (e.g. between dd.mm.yyyy)
. is used to match whichever character (either capital or non-capital)
\w+ matches a sequence of alphanumeric characters (including _), but does not match special characters such as "/"
\d+ matches a series of digits
(.*) is used to match a group (because of ()) of 0 or more of any character (because of .*); it useful for cases where there is no whitespace after the dot (e.g. "end of sentence.Comparatif")
[Cc] is used to match the letter "c" which could be either capital or non-capital
? indicates that a char (or group) is optional. E.g. "aa?" will match either one or two letters "a" cause the second char is optional
| is used to reproduce the logical OR. E.g. re.compile("Sent from (iPhone|iPod)") to match either iPhone OR iPod
secret[\.,] is used to match the word "secret" followed either by a "." or a ","
(secret)[.,] is used to match only the word "secret" and get rid of the punctuation that comes after it

re.search(r"smth", file) finds only the first match, and also provides the indexes of the match in the text
re.findall(r"smth", file) finds all the matches, but we lose the information about the indexes
re.finditer(r"smth", file) finds all the matches and also retains the indexes. It must be run as:

for match in re.finditer(r"(secret)[\.,]", file_content):
   print(match)