How do I control the order of keys when converting a Python dictionary to JSON using \'json.dumps\'?

JSON Object Key Ordering with "json.dumps"

Problem:

When converting a Python dictionary to a JSON object using "json.dumps," the order of the keys may not be as expected. The desired order (e.g., "id," "name," "timezone") is not being maintained.

Solution:

1. Sort Keys:

To specify the desired key order, pass the "sort_keys" parameter to "json.dumps." This parameter sorts the keys in ascending order.

json.dumps(countries, sort_keys=True)

2. Use "OrderedDict":

For precise control over the key order, use the "OrderedDict" from the "collections" module instead of a regular dictionary. The order of keys in "OrderedDict" is preserved upon conversion to JSON.

Python 3.7 and Below:

import json
from collections import OrderedDict

ordered_countries = OrderedDict([("id", row.id), ("name", row.name), ("timezone", row.timezone)])
print(json.dumps(ordered_countries))

Python 3.8 and Above:

import json
from collections import OrderedDict

ordered_countries = OrderedDict()
ordered_countries["id"] = row.id
ordered_countries["name"] = row.name
ordered_countries["timezone"] = row.timezone
print(json.dumps(ordered_countries))

3. Preserving Input Order (JSON):

If the input is already a JSON object and you want to preserve its key order in the output, pass the "object_pairs_hook" parameter to "json.loads." This parameter takes a callable that returns an "OrderedDict" based on the key-value pairs of the JSON object.

import json
from collections import OrderedDict

input_json = '{"a": 1, "b": 2}'
ordered_json = json.loads(input_json, object_pairs_hook=OrderedDict)

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