Regex_Cheat_Sheet.txt

https://docs.python.org/2/library/re.html

r"Monish"	# match Monish

r"...\....\....\...."	# . matches anything \. matches .

r"^...\....$"	# start and end of the string or same length

r"\d\d\D\d\d\D\d\d\d\d"	# \d digits \D non digits

r"\S\S\s\S\S\s\S\S"	# \s white space \S non white space

r"\w\w\w\W\w\w\w"	#\w word character \W non word character

r'[123]'	# match a charater with any of the characters inside[]

r'[^123]'	# match a charater with any of the characters other than inside[^]

r'[a-z][A-Z][0-9][l-p][B-R]' # match a charater in the range inside []

r'[13579]{5}$'	# match no. of repititions in {}

r'^\d{1,2}[A-Z]{3,}\.{,3}$'# match with repetitions in{} {lowerlimit,upperlimit} both inclusive or {lowerlimit,} or {,upperlimit}

r'[A-z]*'	# * matches 0 or more repetitions

r'[A-Z]+'	# + matches 1 or more repetitions

r'^(Mr|Mrs|Ms|Dr|Er)\.[A-Za-z]+$'	# (Mr|Mrs|Ms|Dr|Er) matches either of these 

r'\b[AEIOUaeiou][A-Za-z]*\b'	# \b matches word boundary

r'(ok){3,}'	# () lets us operate on exact phrase

r'^([a-z])(\w)(\s)(\W)(\d)(\D)([A-Z])([a-zA-Z])([aeiouAEIOU])(\S)\1\2\3\4\5\6\7\8\9\10'	# \1 \2 etc match group no. captured

'/^(?|(-)|(---)|(:)|(\.))\1$/'; // check for any of these groups (?|regex)

^(\\2tic|(tac))+$ // detect tactactic forward reference

o(?=oo) // detects ooo positive lookaheado(?=oo)

"(\\S)(?!\\1)") //detects 3 repeated characters negative lookahead (?!)

"(?<=[\\w])[13579]" // positive look behind odd digit followed by all occurences of digit

"(?<![aeiouAEIOU])(\\s|\\S)" // negative look behind match occurences of characters which are not immediately preceded by vowels