Learning something new every day

Here's one for all you progammers out there: what happens to the values of x and y if you type the following in, say, Python?

>>> x = 5
>>> y = 6
>>> x,y = y,x

I'd always half-thought, without really considering it, that you'd end up with x=6 and y=6, i.e. that the above was syntactic sugar for:

>>> x = y
>>> y = x

Actually, though, it turns out...

>>> x=5
>>> y=6
>>> x,y=y,x
>>> print x,y
6 5