code: def concat(objs, axis=0, join='outer', join_axes=None, ignore_index=False,
             keys=None, levels=None, names=None, verify_integrity=False,
             sort=None, copy=True):
      op = _Concatenator(objs, axis=axis, join_axes=join_axes,
                         ignore_index=ignore_index, join=join,
                         keys=keys, levels=levels, names=names,
                         verify_integrity=verify_integrity,
                         copy=copy, sort=sort)
      return op.get_result()