JSON

JSON is the text format the web uses to exchange data. It looks almost exactly like Python dicts and lists.

import json
data = json.loads('{"a": [1, 2]}')   # text -> Python
text = json.dumps(data)              # Python -> text

JSON uses lowercase true, false, and null inside its text. loads converts them to Python True, False, and None; dumps converts them back.

See it run

import json
order = {"id": 7, "tags": ["new", "gift"], "paid": True}
text = json.dumps(order)
back = json.loads(text)
back["paid"] = False
print(text)
print(order["paid"])

JSON is just text. dumps turns Python data into it, loads turns it back.

Practice json

Exercise 1

Parse text from the code editor below into data.
first_skill = the first item of data["skills"].
Add the key "level" with 3 to data, then turn it back into a string back.

Exercise 2

Parse the shipment JSON in text in the code editor below into shipment. Sum quantities from every item into units; keep zero quantities. Add "units" to shipment and serialize the complete updated object into back.

Exercise 3

Write active_names(text) for a JSON list of user objects. Return a JSON string containing only the names whose active field is true; a missing active field means false. Preserve order and repeated names, and support an empty list.

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Practice

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Visualizer Watch your code run line by line

Run your code, then choose Play to follow its execution.

Memory · names → values

Variables appear here as Python creates them.

Output & plots