def SumSq(a,b):
  return [a+b, a+b*b]

s = [-5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5]

def Sum(a,b):
  return SumSq(a,b)[0]

def Sq(a,b):
  return SumSq(a,b)[1]

print "Sum =",reduce(Sum, s)
print "Sum2 =",reduce(Sq, s, 0)
print "Average = ",reduce(Sum, s)/float(len(s))
print "Variance = ",reduce(Sq, s, 0)/float(len(s))