Python random helper functions

random_string.py

from sys import maxint
from random import choice, sample, shuffle
from string import ascii_uppercase as U, ascii_lowercase as L, digits as D, punctuation as P

def populate(punctuation, extra):
    chars = U + L + D
    if isinstance(extra, basestring):
        chars += extra
    if punctuation:
        chars += P
    return chars
    
''' random string of size N - repeating elements '''
def randomizer(N=60, punctuation=True, extra=''):
    return "".join([ choice(populate(punctuation, extra) for n in range(N) ]

''' random string of size K - unique elements                 '''
''' (but can be repeatable if you add same elements to extra) '''
def sampler(K=10, punctuation=True, extra=''):
    return sample(populate(punctuation, extra), K)

''' return a shuffled copy of a list '''
def shuffler(L):
    C = L[:]
    shuffle(C)
    return C
    
''' returns a generator providing random integers '''
def ranger(N=10, a=None, b=None):
    if a is None:
        a = -(maxint + 1)
    if b is None:
        b = maxint
    return (randint(a,b) for n in xrange(N))