We can select string with some patterns.
import re
. matches any character except a newline^a all strings starting with 'a'a$ all strings ending with 'a'ab+ matches 'ab', 'abb' but not 'a', 'ac'.[bcr]at any characters within [] can be filled the space\\\\ to escape special characters
\\\\s : whitespace characters. \\\\S: any except whitespace.\\\\b : empty strings (only at the beginning or end of a word). \\\\B:cat|dog would match 'catfish' and 'hotdog' for begin and end characters[amk] will match 'a', 'm', or `'k``[0-9] will match any character that falls between 0 and 9[a-z] : lowercase[0-9]{4}: repeat the pattern [0-9] four times by writinga{m,n} matches from m to n repetitions of 'a'.
a{m,} matches from m to infinity repetitions of 'a'.