Common characer classes

\d \w \s

• \d digit: Unicode Characters in the 'Number, Decimal Digit' Category or [0-9] if re.ASCII is enabled.

• \w word character. See the Unicode alphanumeric characters (digits and letters) or [a-zA-Z0-9_] (digits, letters, underscore) if re.ASCII is enabled.

• \s white space: Unicode whitespace characters or [\f\t\n\r\v ] form-feed, tab, newline, carriage return, vertical-tab, and SPACE if re.ASCII is enabled.

• Use stand alone: \d or as part of a larger character class: [abc\d]