python: clopper pearson binomial confidence belt

gistfile1

import scipy.stats
def clopper_pearson(k,n,alpha=0.32):
    """
    http://en.wikipedia.org/wiki/Binomial_proportion_confidence_interval
    alpha confidence intervals for a binomial distribution of k expected successes on n trials
    Clopper Pearson intervals are a conservative estimate.
    """
    lo = scipy.stats.beta.ppf(alpha/2, k, n-k+1)
    hi = scipy.stats.beta.ppf(1 - alpha/2, k+1, n-k)
    return lo, hi