6 raise TypeError("The number list was not a list of numbers.")
8 print "There was a problem evaluating the number list."
13 assert mean([0, 0, 0, 0]) == 0
14 assert mean([0, 200]) == 100
15 assert mean([0, -200]) == -100
19 def test_floating_mean():
20 assert mean([1, 2]) == 1.5