Question

I am in simple doubt… I created the following dictionary:

>>> alpha={'a': 10, 'b': 5, 'c': 11}

But, when I want to see the dictionary keys and values I got:

>>> alpha
{'a': 10, 'c': 11, 'b': 5}

See that the “b” and “c” has swapped their position. How can I make the position be the same of the moment that the dictionary was created?

Answer 1

Dictionaries are unordered containers – if you want to preserve order, you can use collections.OrderedDict (Python 2.7 or later), or use another container type which is naturally order-preserving.

Generally if you have an access pattern that cares about ordered retrieval then a dictionary is solving a problem you don’t have (fast access to random elements), while giving you a new one.