RegEx

Metacharacters

• .: Any character (except newline character)
• ^: Starts with
• $: Ends with
• *: Zero or more occurrences
• +: One or more occurrences
• ?: Zero or one 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
• \B: Returns a match where the specified characters are present, but NOT at the beginning (or at the end) of a word
• \d: Any digit (0-9)
• \D: Any non-digit character
• \s: Any whitespace character
• \S: Any non-whitespace character
• \w: Any word character (a-z, A-Z, 0-9, _)
• \W: Any non-word character
• \Z: Returns a match if the specified characters are at the end of the string

Sets

• [abc]: Will match any of the characters a, b, or c
• [^abc]: Matches any character except a, b, or c
• [a-z]: Matches any lowercase character
• [A-Z]: Matches any uppercase character
• [0-9]: Matches any digit
• [a-zA-Z]: Matches any alphabet character (both lowercase and uppercase)
• [0-9a-zA-Z]: Matches any alphanumeric character

Python Functions

• re.findall(): Returns a list containing all matches
• re.search(): Returns a Match object if there is a match anywhere in the string
• re.split(): Returns a list where the string has been split at each match
• re.sub(): Replaces one or many matches with a string