Master Python JSON: Read, Write, Parse, and Serialize with Real Code

Python JSON Overview

JSON (JavaScript Object Notation) is a lightweight, text‑based data interchange format inspired by JavaScript. It is widely used to store and transmit semi‑structured data between browsers and servers.

Reading JSON Files in Python

Python’s built‑in json module can read JSON files without extra installation. Example:

import json
with open('data.json') as f:
    data = json.load(f)
print(data)

Parsing JSON Strings

Use json.loads() to convert a JSON string into a Python dictionary or list, and json.dumps() to convert Python objects back to JSON strings.

import json
people_string = '''
{
  "people": [
    {"emp_name": "John smith", "emp_no.": "924367-567-23", "emp_email": ["[email protected]"], "has_license": false},
    {"emp_name": "harshit kant", "emp_number": "560-555-5153", "emp_email": null, "has_license": true}
  ]
}
'''
data = json.loads(people_string)
print(data)
print(type(data))

Converting Python Objects to JSON

Use json.dumps() to serialize Python data structures into JSON strings.

import json
new_string = json.dumps(data, sort_keys=True, indent=3)
print(new_string)

Parsing JSON with Pandas

Pandas can directly read JSON files into DataFrames.

import pandas as pd
import json
with open('nobel_prize.json') as f:
    data = json.load(f)
df = pd.DataFrame(data)
print(df)

JSON Serialization (Encoding)

Serialization converts Python objects (e.g., dict) into JSON using json.dump() for files or json.dumps() for strings.

import json
with open('new_nobel_prize.json', 'w') as f:
    json.dump(data, f, indent=2)

Key functions: dump() – write JSON to a file dumps() – return JSON string load() – read JSON file into Python loads() – parse JSON string into Python

Pretty Printing JSON

Use json.dumps() with sort_keys=True and indent to produce human‑readable output.

import json
pretty = json.dumps(data, sort_keys=True, indent=3)
print(pretty)

JSON Deserialization (Decoding)

Deserialization reverses serialization, converting JSON back to Python objects using json.load() or json.loads().

Full Example: Serialize and Deserialize a Nobel Prize Dataset

import json
# Serialize
with open('nobel_prize.json') as f:
    data = json.load(f)
with open('new_nobel_prize.json', 'w') as f:
    json.dump(data, f, indent=2)
# Deserialize and iterate
with open('nobel_prize.json') as f:
    data = json.load(f)
for prize in data['prizes']:
    print(prize['year'], prize['category'])

Output shows each prize’s year and category.