uuid64.py

#!/usr/bin/env python

"""
Functions to represent UUIDs as Base64 strings.

Base64 typically uses '+' and '/' as encoding characters. Neither are URL-safe,
so these functions use ',' and '-'. The characters '.' and '_' were considered,
but rejected, as some web frameworks will treat any URL fragment starting with
them as a hidden resource.
"""

import uuid
import base64

ALTCHARS=',-'


def uuid_to_ascii(u=None):
    """
    Convert or create a UUID and return as a Base64 string.
    """
    if u is None:
        u = uuid.uuid4()
    return base64.b64encode(u.bytes, altchars=ALTCHARS).replace('=', '')

def ascii_to_uuid(ascii):
    """
    Convert an ASCII string back into a UUID. The string must
    have been created by :func:`uuid_to_ascii`.
    """
    ascii = ascii +  '=' * (len(ascii) % 4)
    return uuid.UUID(bytes=base64.b64decode(ascii, altchars=ALTCHARS))

def _test():
    print "Testing with a hundred random UUIDs..."
    print
    for x in range(100):
        u1 = uuid.uuid4()
        a = uuid_to_ascii(u1)
        u2 = ascii_to_uuid(a)
        print "UUID: %s, ASCII: %s" % (str(u1), a)
        assert u1 == u2

if __name__ == '__main__':
    _test()