def __iter__(self):
        return self._data.iterkeys()

    # Three-way comparison is not supported.  However, because __eq__ is
    # tried before __cmp__, if Set x == Set y, x.__eq__(y) returns True and
    # then cmp(x, y) returns 0 (Python doesn't actually call __cmp__ in this
    # case).
Return an iterator over the elements or a set.
dataset/ETHPy150Open azoft-dev-team/imagrium/env/Lib/sets.py/BaseSet.__iter__