Python requests.Session Class

The requests.Session class in Python’s requests module allows you to persist certain parameters across multiple requests. It helps to maintain cookies, headers, and connection pooling for better performance and convenience when making multiple requests to the same host.

Table of Contents

1. Introduction
2. requests.Session Class Syntax
3. Examples
   • Basic Usage
   • Persisting Headers
   • Maintaining Cookies
   • Session with Authentication
   • Handling JSON Responses
4. Real-World Use Case
5. Conclusion

Introduction

The requests.Session class is part of the requests module, which makes it easy to make HTTP requests in Python. Using a session object, you can persist certain parameters across requests, such as headers and cookies, which can be useful when interacting with web services that require stateful interactions.

requests.Session Class Syntax

Here’s how you use the requests.Session class:

import requests

session = requests.Session()
response = session.request(method, url, **kwargs)

Common Methods:

• session.get(url, **kwargs)
• session.post(url, **kwargs)
• session.put(url, **kwargs)
• session.delete(url, **kwargs)
• session.head(url, **kwargs)
• session.options(url, **kwargs)
• session.patch(url, **kwargs)

Parameters:

• url: The URL for the request.
• **kwargs: Optional arguments to customize the request.

Returns:

• A Response object containing the server’s response to the HTTP request.

Examples

Basic Usage

Create a session and send a GET request.

import requests

session = requests.Session()
response = session.get('https://jsonplaceholder.typicode.com/posts/1')
print(response.json())

Output:

{'userId': 1, 'id': 1, 'title': 'sunt aut facere repellat provident occaecati excepturi optio reprehenderit', 'body': 'quia et suscipit\nsuscipit recusandae consequuntur expedita et cum\nreprehenderit molestiae ut ut quas totam\nnostrum rerum est autem sunt rem eveniet architecto'}

Persisting Headers

Persist headers across multiple requests using a session.

import requests

session = requests.Session()
session.headers.update({'Authorization': 'Bearer your_token'})

response = session.get('https://jsonplaceholder.typicode.com/posts/1')
print(response.json())

response = session.get('https://jsonplaceholder.typicode.com/posts/2')
print(response.json())

Output:

{'userId': 1, 'id': 1, 'title': 'sunt aut facere repellat provident occaecati excepturi optio reprehenderit', 'body': 'quia et suscipit\nsuscipit recusandae consequuntur expedita et cum\nreprehenderit molestiae ut ut quas totam\nnostrum rerum est autem sunt rem eveniet architecto'}
{'userId': 1, 'id': 2, 'title': 'qui est esse', 'body': 'est rerum tempore vitae\nsequi sint nihil reprehenderit dolor beatae ea dolores neque\nfugiat blanditiis voluptate porro vel nihil molestiae ut reiciendis\nqui aperiam non debitis possimus qui neque nisi nulla'}

Maintaining Cookies

Maintain cookies across multiple requests.

import requests

session = requests.Session()
session.get('https://httpbin.org/cookies/set/sessioncookie/123456789')

response = session.get('https://httpbin.org/cookies')
print(response.json())

Output:

{'cookies': {'sessioncookie': '123456789'}}

Session with Authentication

Use a session with authentication.

import requests

session = requests.Session()
session.auth = ('user', 'pass')

response = session.get('https://httpbin.org/basic-auth/user/pass')
print(response.json())

Output:

{'authenticated': True, 'user': 'user'}

Handling JSON Responses

Send a POST request with JSON data and handle the JSON response.

import requests

session = requests.Session()
json_data = {'title': 'foo', 'body': 'bar', 'userId': 1}

response = session.post('https://jsonplaceholder.typicode.com/posts', json=json_data)
print(response.json())

Output:

{'title': 'foo', 'body': 'bar', 'userId': 1, 'id': 101}

Real-World Use Case

Making Multiple Requests to an API

Use a session to make multiple requests to an API that requires authentication and maintain state across requests.

import requests

session = requests.Session()
session.headers.update({'Authorization': 'Bearer your_token'})

# Get user data
response = session.get('https://jsonplaceholder.typicode.com/users/1')
user_data = response.json()
print(user_data)

# Post a new post as the user
json_data = {'title': 'foo', 'body': 'bar', 'userId': user_data['id']}
response = session.post('https://jsonplaceholder.typicode.com/posts', json=json_data)
print(response.json())

Output:

{'id': 1, 'name': 'Leanne Graham', 'username': 'Bret', 'email': 'Sincere@april.biz', 'address': {'street': 'Kulas Light', 'suite': 'Apt. 556', 'city': 'Gwenborough', 'zipcode': '92998-3874', 'geo': {'lat': '-37.3159', 'lng': '81.1496'}}, 'phone': '1-770-736-8031 x56442', 'website': 'hildegard.org', 'company': {'name': 'Romaguera-Crona', 'catchPhrase': 'Multi-layered client-server neural-net', 'bs': 'harness real-time e-markets'}}
{'title': 'foo', 'body': 'bar', 'userId': 1, 'id': 101}

Conclusion

The requests.Session class is used for making HTTP requests in Python. It allows you to persist headers, cookies, and other parameters across multiple requests, which can simplify your code and improve performance when interacting with web services and APIs.