title: Python: Anyway to use map to get first element of a tuple
body: <p>I have a tuple of tuples and I want to put the first value in each of the tuples into a set. I thought using map() would be a good way of doing this the only thing is I can't find an easy way to access the first element in the tuple. So for example I have the tuple <code>((1,), (3,))</code>. I'd like to do something like <code>set(map([0], ((1,), (3,))))</code> (where <code>[0]</code> is accessing the zeroth element) to get a set with 1 and 3 in it. The only way I can figure to do it is to define a function: <code>def first(t): return t[0]</code>. Is there anyway of doing this in one line without having to declare the function?</p>