def variance(self):
        mean = float(sum(self))/len(self)
        summation = 0
        for num in self:
            summation += (num - mean)**2
        return summation/len(self)
Returns the given number formatted for the current locale. Example::
dataset/ETHPy150Open sightmachine/SimpleCV/SimpleCV/LineScan.py/LineScan.variance--crossover with--dataset/ETHPy150Open AppScale/appscale/AppServer/lib/webapp2-2.3/webapp2_extras/i18n.py/I18n.format_number