Regular expression in is a sequence of characters that forms a search pattern.
It is used to confirm whether the string has that particular term or not.
We can easily import regular expression in python.
- [] – A set of characters
- \ – Signals a special sequence.
- . – Any character
- ^ – Starts with
- $ – Ends with
- * – Zero or more occurrence
- + – One or more occurrence
- {} – Exactly the specified number of occurrences.
- | – Either or
- () – Capture and group
- \d Matches any decimal digit, this is equivalent to the set class [0-9].
- \D Matches any non-digit character.
- \s Matches any whitespace character.
- \S Matches any non-whitespace character
- \w Matches any alphanumeric character, this is equivalent to the class [a-zA-Z0-9_].
- \W Matches any non-alphanumeric character.
- (?:re) – Groups regular expression without remembering matched text.
- (?imx: re) – Temporarily toggles on i,m or x options within parentheses.
- (?#…) – comment
- (?! re) – Specifies position using pattern negation. Doesn’t have a range.
- (? > re) Matches independent pattern without backtracking.
This is all about patterns in regular expression in python.
