DontRunMeOver

It looks very weird but it makes sense too.

Pythons, well snakes in general, don't chew their food (they only have sharp, fang teeth which can't be used for chewing) or manipulate it outside of their body (they have no limbs!). They swallow their food whole. Once inside the body the muscle which run along the snake squeeze in on the food, crushing it, while the digestive juices also help to dissolve the food. As the snake's body is also very flexible and stretchy they can swallow things which are wider than their own body (have you seen a small snake eating an egg?) and so can generally be optimistic about the size of food they are able to eat.

As the python (like the ones in this picture) is so big it probably doesn't meet many situations in which its prey is too large for it to digest. As a result it might have lost the instinct which other snakes probably have which tell it when something is too large to eat. So when it comes across a massive alligator it doesn't stop to think 'will I be able to eat this' and just starts chomping away until its insides burst!