How do I convert an iterator over bytes into a str?

[markscottwright]

This does what I expected:
    In [6]: list(iter([1,2,3,4,5]))
    Out[6]: [1, 2, 3, 4, 5]

But this appears to be doing a __repr__ rather than making me a nice
string:
   In [7]: str(iter("four score and seven years ago"))
   Out[7]: '<iterator object at 0x0139F190>'

What's the correct way to turn an iterator over bytes into a string?
This works, but, ewww:
    In [8]: "".join(iter("four score and seven years ago"))
    Out[8]: 'four score and seven years ago'