Last Key in Python Dictionary

Question

I am having difficulty figuring out what the syntax would be for the last key in a Python dictionary. I know that for a Python list, one may say this to denote the last:

Answer 1

If insertion order matters, take a look at collections.OrderedDict:

An OrderedDict is a dict that remembers the order that keys were first inserted. If a new entry overwrites an existing entry, the original insertion position is left unchanged. Deleting an entry and reinserting it will move it to the end.

---

In [1]: from collections import OrderedDict

In [2]: od = OrderedDict(zip('bar','foo'))

In [3]: od
Out[3]: OrderedDict([('b', 'f'), ('a', 'o'), ('r', 'o')])

In [4]: od.keys()[-1]
Out[4]: 'r'

In [5]: od.popitem() # also removes the last item
Out[5]: ('r', 'o')

Update:

An OrderedDict is no longer necessary as dictionary keys are officially ordered in insertion order as of Python 3.7 (unofficially in 3.6).

For these recent Python versions, you can instead just use list(my_dict)[-1] or list(my_dict.keys())[-1].