Python choose random number in specific interval

If this is Python 2 there is a problem with

random.randint(10, 200) / 100

because the division will be done in integer math. You should use

random.randint(10, 200) / 100.

Another problem is that you are choosing the random step at every update (probably every frame) and this will not give the illusion of a speed, but more of a randomly jerky movement. It would probably be better to choose a random speed like your are doing but keeping it the same at least for a few frames or even for the whole fall animation.