cybertools/util/randomname.py
helmutm 78f0320c57 use static character list
git-svn-id: svn://svn.cy55.de/Zope3/src/cybertools/trunk@1890 fd906abe-77d9-0310-91a1-e0d9ade77398
2007-08-09 11:36:19 +00:00

55 lines
1.6 KiB
Python

#
# Copyright (c) 2007 Helmut Merz helmutm@cy55.de
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
#
"""
Generate strange (not guessable) UIDs.
$Id$
"""
import random
charList = ([chr(i) for i in range(48, 58)]
+ [chr(i) for i in range(97, 123)]
+ [chr(i) for i in range(65, 91)]
+ ['-', '_']
)
def generateName(check=None, lowerCaseOnly=False, bits=128, base=62, seed=None):
""" Generates an unguessable random name.
"""
if base > 64:
raise ValueError('The base argument may not exceed 64, but is %i.' % base)
random.seed(seed)
OK = False
base = lowerCaseOnly and min(base, 36) or base
while not OK:
data = strBase(random.getrandbits(bits), base)
OK = check is None or check(data)
return data
def strBase(n, base):
result = []
while n > 0:
n, r = divmod(n, base)
result.append(r)
return ''.join(reversed([charList[n] for n in (result or [0])]))