def confidence(ups, downs):
    n = ups + downs
if n == 0:
    return 0
z = 1.0
phat = float(ups) / n
return (phat + z * z / (2 * n) - z * sqrt((phat * (1 - phat) + z * z / (4 *
    n)) / n)) / (1 + z * z / n)
Python implementation of the Wilson Score Interval?