Split a dictionary in half?

Question

What is the best way to split a dictionary in half?

d = {'key1': 1, 'key2': 2, 'key3': 3, 'key4': 4, 'key5': 5} 

I'm looking to do this:

d1 = {'key1': 1, 'key2': 2, 'key3': 3} d2 = {'key4': 4, 'key5': 5} 

It does not matter which keys/values go into each dictionary. I am simply looking for the simplest way to divide a dictionary into two.

Answer 1

This would work, although I didn't test edge-cases:

>>> d = {'key1': 1, 'key2': 2, 'key3': 3, 'key4': 4, 'key5': 5} >>> d1 = dict(d.items()[len(d)/2:]) >>> d2 = dict(d.items()[:len(d)/2]) >>> print d1 {'key1': 1, 'key5': 5, 'key4': 4} >>> print d2 {'key3': 3, 'key2': 2} 

In python3:

d = {'key1': 1, 'key2': 2, 'key3': 3, 'key4': 4, 'key5': 5} d1 = dict(list(d.items())[len(d)//2:]) d2 = dict(list(d.items())[:len(d)//2]) 

Also note that order of items is not guaranteed

Answer 2

Here's a way to do it using an iterator over the items in the dictionary and itertools.islice:

import itertools  def splitDict(d):     n = len(d) // 2          # length of smaller half     i = iter(d.items())      # alternatively, i = d.iteritems() works in Python 2      d1 = dict(itertools.islice(i, n))   # grab first n items     d2 = dict(i)                        # grab the rest      return d1, d2