Python’s string module provides constants for string related operations. To use them, import the string module:

>>> import string

string.ascii_letters:

Concatenation of ascii_lowercase and ascii_uppercase:

>>> string.ascii_letters
'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'

string.ascii_lowercase:

Contains all lower case ASCII characters:

>>> string.ascii_lowercase
'abcdefghijklmnopqrstuvwxyz'

string.ascii_uppercase:

Contains all upper case ASCII characters:

>>> string.ascii_uppercase
'ABCDEFGHIJKLMNOPQRSTUVWXYZ'

string.digits:

Contains all decimal digit characters:

>>> string.digits
'0123456789'

string.hexdigits:

Contains all hex digit characters:

>>> string.hexdigits
'0123456789abcdefABCDEF'

string.octaldigits:

Contains all octal digit characters:

>>> string.octaldigits
'01234567'