# -*- coding: utf-8 -*-
from __future__ import (absolute_import, division, print_function)

from collections import OrderedDict
from .pyutil import defaultnamedtuple

dimension_codes = OrderedDict(zip(
    'length mass time current temperature luminous_intensity amount'.split(),
    'L M T I Θ N J'.split()
))


class DimensionalitySI(defaultnamedtuple('DimensionalitySIBase', dimension_codes.keys(), (0,)*len(dimension_codes))):

    def __mul__(self, other):
        return self.__class__(*(x+y for x, y in zip(self, other)))

    def __truediv__(self, other):
        return self.__class__(*(x-y for x, y in zip(self, other)))

    def __pow__(self, exp):
        return self.__class__(*(x*exp for x in self))

base_registry = {name: DimensionalitySI(**{tok: 1}) for name, tok in dimension_codes.items()}

@@ -751,19 +751,20 @@
 tySI(**%7B
-tok
+name
 : 1%7D) fo
@@ -773,13 +773,8 @@
 name
-, tok
  in 
@@ -792,14 +792,6 @@
 odes
-.items()
 %7D%0A

Fix _dimensionality.py