Consuming JSON APIs in Python (with requests and json Modules)

Introduction

APIs often return data in JSON format, a lightweight and human-readable data interchange format. Python's requests and json libraries make it easy to consume RESTful JSON APIs.

Required Modules

Install requests (if not installed):

pip install requests

Then import:

import requests
import json

1. Making a GET Request to a JSON API

import requests

response = requests.get("https://jsonplaceholder.typicode.com/posts/1")
print("Status Code:", response.status_code)
print("JSON Response:", response.json())

Output:

Status Code: 200
JSON Response: {'userId': 1, 'id': 1, 'title': '...', 'body': '...'}

2. Accessing JSON Fields from Response

data = response.json()
print("Title:", data['title'])
print("Body:", data['body'])

3. Consuming a JSON API that Returns an Array

response = requests.get("https://jsonplaceholder.typicode.com/posts")
data = response.json()

# Print first 3 posts
for post in data[:3]:
    print(post['id'], post['title'])

Output:

1 sunt aut facere repellat
2 qui est esse
3 ea molestias quasi

4. POST Data to a JSON API

url = "https://jsonplaceholder.typicode.com/posts"
payload = {
    "title": "Python API Demo",
    "body": "This is from Python!",
    "userId": 1
}

response = requests.post(url, json=payload)
print("Status Code:", response.status_code)
print("Response JSON:", response.json())

Output:

{
  'title': 'Python API Demo',
  'body': 'This is from Python!',
  'userId': 1,
  'id': 101
}

5. Send Headers with API Request

headers = {'Content-Type': 'application/json'}
response = requests.get("https://jsonplaceholder.typicode.com/posts", headers=headers)
print(response.status_code)

6. Handle API Errors Gracefully

response = requests.get("https://jsonplaceholder.typicode.com/invalid-url")

if response.status_code == 404:
    print("API endpoint not found.")
else:
    print("Success!")

7. Save JSON Response to a File

with open('data.json', 'w') as f:
    json.dump(response.json(), f, indent=4)