Why are Python sets not considered sequences?

Question

In the python documentation for versions 2.x it says explicitly that there are seven sequence data types. The docs go on to discuss sets and tuples some time later (on the same page), both of which are not included in the above seven. Does anyone know what exactly makes defines a sequence type? My intuited definition has sets and tuples fitting the bill quite nicely, and I haven't had any luck finding an explicit official definition.

Thanks!

Answer 1

The word "sequence" implies an order, but sets are not in a specific order.