Slicing a Python OrderedDict

Question

In my code I frequently need to take a subset range of keys+values from a Python OrderedDict (from collections package). Slicing doesn\'t work (throws Typ

Answer 1

You can use the itertools.islice function, which takes an iterable and outputs the stop first elements. This is beneficial since iterables don't support the common slicing method, and you won't need to create the whole items list from the OrderedDict.

from collections import OrderedDict
from itertools import islice
o = OrderedDict([('a', 1), ('b', 2), ('c', 3), ('d', 4)])
sliced = islice(o.iteritems(), 3)  # o.iteritems() is o.items() in Python 3
sliced_o = OrderedDict(sliced)