So changing this to:
```python
import math
import operator
from functools import reduce
from collections import Mapping

import numpy as np

from distarray.externals import six
from distarray.externals.six import next
from distarray.externals.six.moves import zip
from distarray.mpiutils import MPI
from distarray.utils import _raise_nie
from distarray.local import construct, format, maps
from distarray.local.error import InvalidDimensionError, IncompatibleArrayError
```