Working with JSON

JSON (JavaScript Object Notation) is a popular data format.

Reading JSON

import json

# Read from file
with open('data.json', 'r') as file:
    data = json.load(file)
    print(data)

# Parse JSON string
json_string = '{"name": "Alice", "age": 25}'
data = json.loads(json_string)

Writing JSON

import json

data = {
    "name": "Alice",
    "age": 25,
    "hobbies": ["reading", "coding"]
}

# Write to file (pretty formatted)
with open('output.json', 'w') as file:
    json.dump(data, file, indent=4)

# Convert to string
json_string = json.dumps(data, indent=2)

Nested JSON

data = {
    "users": [
        {"name": "Alice", "age": 25},
        {"name": "Bob", "age": 30}
    ],
    "total": 2
}

# Access nested data
first_user = data["users"][0]
print(first_user["name"])

JSON vs Dictionary

# Python dict → JSON
python_dict = {"name": "Alice", "active": True}
json_string = json.dumps(python_dict)

# JSON → Python dict
json_string = '{"name": "Bob", "age": 30}'
python_dict = json.loads(json_string)

Practice Exercises

1. Read and parse JSON file
2. Write dictionary to JSON
3. Update JSON file
4. Convert CSV to JSON
5. Work with nested JSON data

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