def variancediy2(data):
    n = len(data)
    if n>1:
        mean = sum(data) / n
    else:
        mean = sum(data)
    deviations = [(x - mean) ** 2 for x in data]
    if n >1:
        variance2 = sum(deviations) / (n-1)
    else:
        variance2 = sum(deviations)
    return variance2