Concatenation of the ascii_lowercas and ascii_uppercase constants.

Sequence of lowercase letters 'abcdefghijklmnopqrstuvwxyz'.

Sequence of uppercase letters 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'.

Sequence of decimal digits '0123456789'.

Sequence of hexadecimal digits '0123456789abcdefABCDEF'.

Sequence of octal digits '01234567'.

Sequence of ASCII characters which are considered printable: digits, ascii_letters, punctuation, and whitespace.

Sequence of ASCII characters which are considered punctuation: !"#$%&'()*+,-./:;<=>?@[\]^_{|}~`

Sequence of ASCII characters which are considered whitespace: space, tab, linefeed, return, formfeed, and vertical tab.