def __iter__(self):

        # obtain ctable
        if isinstance(self.source, string_types):
            import bcolz
            ctbl = bcolz.open(self.source, mode='r')
        else:
            # assume bcolz ctable
            ctbl = self.source

        # obtain header
        if self.outcols is None:
            header = tuple(ctbl.names)
        else:
            header = tuple(self.outcols)
            assert all(ctbl.names in h for h in header), 'invalid outcols'
        yield header

        # obtain iterator
        if self.expression is None:
            it = ctbl.iter(outcols=self.outcols, skip=self.skip,
                           limit=self.limit)
        else:
            it = ctbl.where(self.expression, outcols=self.outcols, skip=self.skip,
                           limit=self.limit)

        for row in it:
            yield row
dataset/ETHPy150Open alimanfoo/petl/petl/io/bcolz.py/BcolzView.__iter__/swapped operands of `in`