old_contents: from stats import *
  
  # Alabama, Alaska, ..., Wyoming alchohol consumption
  beer_per_cap = [21.94, 22, 24.19, 19.58, 19.04, 23.31, 16.94, 25.43, 23.93, 20.26, 24.12, 20.86, 22.2, 19.97, 25.02, 21.12, 19.06, 26.4, 23.25, 18.45, 20.12, 20.59, 21.8, 25.09, 23.79, 30.3, 25.63, 30.62, 31.61, 17.23, 26.15, 16.84, 21.2, 30.41, 23.41, 20.3, 22.61, 22.08, 20.56, 25.87, 26.88, 21.03, 25.42, 12.67, 23.42, 21, 20.12, 23.34, 27.52, 26.5]
  wine_per_cap = [1.24238268, 2.552182, 2.145361, 0.94119689, 3.1935822, 2.4987453, 3.360638, 3.519633, 2.9281906, 1.5588692, 3.0396061, 2.1405284, 2.1986082, 1.3979203, 0.9813412, 0.94928628, 0.97898253, 1.5799767, 2.6431797, 2.0777099, 3.6961575, 1.7342842, 1.8754873, 0.70148546, 1.6677339, 2.1428993, 1.1796579, 3.8256018, 4.4116669, 3.2394561, 1.7459815, 2.6410147, 1.6767241, 1.15415267, 1.4621656, 0.99553168, 3.0251772, 1.41815774, 3.2586038, 1.4748841, 1.06093604, 1.15305843, 1.3476804, 0.79689661, 3.7446437, 2.2460391, 2.9223839, 0.66951223, 1.9217346, 1.3835459]
  print "mean(beer) =", mean(beer_per_cap)
  print "var(beer) =", var(beer_per_cap)
  
  print "mean(wine) =", mean(wine_per_cap)
  print "var(wine) =", var(wine_per_cap)
  
  x = [1,2,3]
  y = [1,2.5,3.1]
  print
  print "covariance = ", cov(beer_per_cap, wine_per_cap)
  
new_contents: import numpy as np  # np is an alias for the numpy library
  from stats import *
  
  # Alabama, Alaska, ..., Wyoming alchohol consumption
  beer_per_cap = [21.94, 22, 24.19, 19.58, 19.04, 23.31, 16.94, 25.43, 23.93, 20.26, 24.12,
                  20.86, 22.2, 19.97, 25.02, 21.12, 19.06, 26.4, 23.25, 18.45, 20.12, 20.59,
                  21.8, 25.09, 23.79, 30.3, 25.63, 30.62, 31.61, 17.23, 26.15, 16.84, 21.2,
                  30.41, 23.41, 20.3, 22.61, 22.08, 20.56, 25.87, 26.88, 21.03, 25.42,
                  12.67, 23.42, 21, 20.12, 23.34, 27.52, 26.5]
  
  wine_per_cap = [1.24238268, 2.552182, 2.145361, 0.94119689, 3.1935822, 2.4987453,
                  3.360638, 3.519633, 2.9281906, 1.5588692, 3.0396061, 2.1405284, 2.1986082,
                  1.3979203, 0.9813412, 0.94928628, 0.97898253, 1.5799767, 2.6431797,
                  2.0777099, 3.6961575, 1.7342842, 1.8754873, 0.70148546, 1.6677339,
                  2.1428993, 1.1796579, 3.8256018, 4.4116669, 3.2394561, 1.7459815,
                  2.6410147, 1.6767241, 1.15415267, 1.4621656, 0.99553168, 3.0251772,
                  1.41815774, 3.2586038, 1.4748841, 1.06093604, 1.15305843, 1.3476804,
                  0.79689661, 3.7446437, 2.2460391, 2.9223839, 0.66951223, 1.9217346,
                  1.3835459]
  
  def test_mean():
      assert np.isclose(mean(beer_per_cap),np.mean(beer_per_cap))
      assert np.isclose(mean(wine_per_cap),np.mean(wine_per_cap))
  
  def test_var():
      assert np.isclose(var(beer_per_cap),np.var(beer_per_cap,ddof=1))
      assert np.isclose(var(wine_per_cap),np.var(wine_per_cap,ddof=1))
  
  def test_cov():
      COV = np.cov(beer_per_cap,wine_per_cap)
      assert np.isclose(cov(beer_per_cap, wine_per_cap),COV[0,1])
  
subject: update point stats test