Controlling the order of dictionary keys
In the Creating dictionaries – inserting and updating recipe, we looked at the basics of creating a dictionary object. In many cases, we'll put items into a dictionary and fetch items from a dictionary individually. The idea of an order to the keys isn't central to using a dictionary.
Here are two common cases where key order may be important:
- Entry order: When working with documents in JSON or YAML notation, it can help to preserve the order of keys from the source documents.
- Sorted order: When summarizing data, it often helps to provide the keys in some easier-to-visualize order.
A Python dictionary's keys – since version 3.6 – are saved in the order in which they were initially inserted. This can be made explicit using the collections.OrderedDict class instead of the built-in dict class.
In the case when a dictionary contains a summary, we may want to sort...
