Biopython does not have support for Uniprot. The reason is because it holds so much data that it would defeat the point to introduce a complex standard that the user would have to try and remember and the best way is for the user to choose themselves what piece of data they want.
Here I discuss the best way to deal with Uniprot XML files using ElementTree, which is really nice, but awkward at times, hence why I talk about a few monkeypatches that help. If you do not wish to deal with ElementTree (say you want a really quick, bu messy fix) see my post about complicated dictionaries.