JSON Persistence

JSON is how programs share structured data — the same format your future APIs will speak.

import json

config = {"theme": "dark", "font_size": 14, "tags": ["work", "urgent"]}

text = json.dumps(config)        # dict -> JSON string
again = json.loads(text)         # JSON string -> dict

And the file versions — the save/load pattern that powers small apps:

import json

def save(contacts, path):
    with open(path, "w", encoding="utf-8") as f:
        json.dump(contacts, f, ensure_ascii=False, indent=2)

def load(path):
    with open(path, encoding="utf-8") as f:
        return json.load(f)

ensure_ascii=False keeps Vietnamese text readable in the file; indent=2 makes it human-inspectable. JSON supports dicts, lists, strings, numbers, booleans, and null — tuples become lists, and anything else needs conversion before saving.