This a small snippet of code I written dozens of times.  It would be nice to have this in the library along with the other distributions.

def binomialvariate(n, p):
    ''' Binomial distribution for the number of successes
        in *n* Bernoulli trials each with a probability *p*
        of success.

        Returns an integer in the range:  0 <= X <= n
    '''
    return sum(random() < p for i in range(n))