Python Requests

Python Requests Library is a simple and powerful tool to send HTTP requests and interact with web resources. It allows you to easily send GET, POST, PUT, DELETE, PATCH, HEAD requests to web servers, handle responses, and work with REST APIs and web scraping tasks.

Features of Python Requests Library

• Simplifies HTTP requests in Python.
• Supports all common HTTP methods.
• Handles cookies, sessions, authentication, SSL verification, etc.
• Great for interacting with APIs and web scraping.

Installation

To install requests library via pip, use the following command:

pip install requests

Syntax

requests.get(url, params={key: value}, **kwargs)

Pramaters:

• url: The URL you want to send the request to. (Required)
• params: Dictionary or bytes to be sent in the query string for GET requests. (Optional)
• **kwargs: Additional optional arguments such as headers, cookies, authentication, timeout, proxies, verify (SSL), stream, etc.

Return Type: It returns a response object.

Making a Simple GET Request

Let's try making a get request to URL: "https://www.geeksforgeeks.org/".

import requests

response = requests.get("https://www.geeksforgeeks.org/")
print(response.status_code)

Explanation:

• requests.get() sends a GET request to the specified URL.
• response.status_code returns the HTTP status code (200 means success).

Sending GET Requests with Parameters

Let's demonstrate how to make a GET request to an endpoint. The GET method sends the encoded user information appended to the page request.

For Example: Let's try making a request to github's APIs for example purposes.

import requests

response = requests.get("https://api.github.com/users/naveenkrnl")
print(response.status_code)
print(response.content)

Output:

For more, visit: GET method – Python requests

HTTP Request Methods

Response object

Whenever you send a request, the server returns a Response object. It contains useful information like status code, headers, content, and more. Response object can be used to imply lots of features, methods, and functionalities.

Example:

import requests

response = requests.get('https://api.github.com/')
print(response.url)
print(response.status_code)

Output:

Explanation:

• response.url returns the final URL after redirections.
• response.status_code shows the HTTP status of the request.
• Status code 200 indicates that request was made successfully.

Response Methods

POST Request Example

import requests

payload = {'username': 'test', 'password': 'test123'}
response = requests.post("https://httpbin.org/post", data=payload)
print(response.text)

Explanation:

• Sends form data to the server.
• data=payload sends the data in the request body.
• The server echoes back the data for testing.

Authentication using Python Requests

Authentication refers to giving a user permissions to access a particular resource. Since, everyone can't be allowed to access data from every URL, one would require authentication primarily. To achieve this authentication, typically one provides authentication data through Authorization header or a custom header defined by server.

Requests module makes this simple using HTTPBasicAuth.

Example:

import requests
from requests.auth import HTTPBasicAuth

response = requests.get(
    'https://api.github.com/user',
    auth=HTTPBasicAuth('user', 'pass')
)

print(response.status_code)

Output:

Explanation:

• Replace 'user' and 'pass' with your credentials (username and password).
• Automatically handles HTTP Basic Authentication.

For more visit - Authentication using Python requests

SSL Certificate Verification

Requests verifies SSL certificates for HTTPS requests, just like a web browser. SSL Certificates are small data files that digitally bind a cryptographic key to an organization's details. Often, an website with a SSL certificate is termed as secure website. By default, SSL verification is enabled, and Requests will throw a SSLError if it’s unable to verify the certificate.

Accessing a site with invalid SSL:

Let us try to access a website with an invalid SSL certificate, using Python requests

import requests

response = requests.get('https://expired.badssl.com/', verify=False)
print(response.status_code)

Output:

Explanation: Setting verify=False disables SSL verification (not recommended for production).

Providing a custom certificate:

The above website doesn't have SSL setup so it raises this error, one can also pass the link to the certificate for validation via python requests only.

import requests

response = requests.get('https://github.com', verify='/path/to/certfile')
print(response.status_code)

This would work in case the path provided is correct for SSL certificate for github.com.

For more visit- SSL Certificate Verification – Python requests

Session Objects

Session objects allow you to persist settings across multiple requests, such as headers, cookies, and connection pooling:. So if several requests are being made to the same host, the underlying TCP connection will be reused, which can result in a significant performance increase. A session object all the methods as of requests.

Using Session Objects

Let us illustrate use of session objects by setting a cookie to a url and then making a request again to check if cookie is set.

import requests

# Create a session object
session = requests.Session()

# Set a cookie
session.get('https://httpbin.org/cookies/set/sessioncookie/123456789')

# Access the cookie in the next request
response = session.get('https://httpbin.org/cookies')
print(response.text)

Output:

Explanation:

• Session() maintains cookies across requests.
• Connection pooling improves performance when making multiple requests to the same server.

For more, visit - Session Objects – Python requests

Error Handling with Requests

You should always handle possible errors:

import requests

try:
    response = requests.get("https://www.example.com", timeout=5)
    response.raise_for_status()
except requests.exceptions.HTTPError as errh:
    print("HTTP Error:", errh)
except requests.exceptions.ConnectionError as errc:
    print("Connection Error:", errc)
except requests.exceptions.Timeout as errt:
    print("Timeout Error:", errt)
except requests.exceptions.RequestException as err:
    print("Something Else:", err)

Explanation:

• Always handle errors like connection issues, timeouts, or bad responses.
• raise_for_status() raises an exception for HTTP errors automatically.