How to Control JSON Key Order with Python\'s `json.dumps`?

JSON Key Order Inconsistencies When Using "json.dumps"

In Python, JSON conversion often entails utilizing "json.dumps" to transform dictionaries into JSON objects. However, users may encounter inconsistencies in the resulting JSON key order, with the expected sequence (id, name, timezone) differing from the actual output (timezone, id, name).

To resolve this issue and enforce the desired key order, two approaches are available:

1. Utilizing the "sort_keys" Parameter:

The "sort_keys" parameter, when set to True, sorts the JSON keys alphabetically. For instance, the following code snippet would yield the desired key order:

<code class="python">import json

countries = []
countries.append({"id": 1, "name": "Mauritius", "timezone": 4})
countries.append({"id": 2, "name": "France", "timezone": 2})
countries.append({"id": 3, "name": "England", "timezone": 1})
countries.append({"id": 4, "name": "USA", "timezone": -4})

json_data = json.dumps(countries, sort_keys=True)
print(json_data)</code>

2. Employing OrderedDict:

Python's "collections.OrderedDict" retains the key insertion order. By utilizing OrderedDict, the expected key order can be achieved:

<code class="python">from collections import OrderedDict

countries = OrderedDict()
countries["id"] = 1
countries["name"] = "Mauritius"
countries["timezone"] = 4

json_data = json.dumps(countries)
print(json_data)</code>

In Python 3.6 and above, keyword argument ordering is preserved by default, allowing for a more concise syntax:

<code class="python">json_data = json.dumps(OrderedDict(id=1, name="Mauritius", timezone=4))
print(json_data)</code>

Lastly, for JSON input, the "object_pair_hook" parameter can be utilized to preserve object order and generate an OrderedDict:

<code class="python">import json

json_data = json.loads('{"id": 1, "name": "Mauritius", "timezone": 4}', object_pairs_hook=OrderedDict)
print(json_data)</code>

The above is the detailed content of How to Control JSON Key Order with Python\'s `json.dumps`?. For more information, please follow other related articles on the PHP Chinese website!