def standard_deviation(r, sample=True):
    avg = average(r)
    sdsq = sum([(i - avg) ** 2 for i in r])
    if sample:
        normal_denom=len(r) - 1 or 1
    else:
        normal_denom=len(r)
    return (sdsq / normal_denom) ** 0.5


#### Number formatting ####
Standard deviation. 
dataset/ETHPy150Open mikeorr/WebHelpers2/webhelpers2/number.py/standard_deviation