In Python, the requests-html library provides a convenient way to manage sessions when making HTTP requests. Sessions allow you to persist certain parameters and headers across multiple requests, making it easier to handle cookies, authentication, and other session-specific information.

In this blog post, we will explore how to use sessions with requests-html to simplify your web scraping or API consuming workflows. Let’s get started!

Installation

First, you need to install the requests-html library. You can do this using pip:

pip install requests-html

Creating a Session

To initiate a session with requests-html, you need to import the HTMLSession class from the library. Here’s an example:

from requests_html import HTMLSession

session = HTMLSession()

Making Requests with a Session

Once you have a session object, you can use it to make HTTP requests. The session object handles things like cookie management automatically, so you don’t need to worry about handling cookies manually.

Here’s an example of making a GET request with a session:

response = session.get('https://example.com')

You can also make other types of requests like POST, PUT, DELETE, etc., by calling the respective method on the session object.

Session Persistence

One of the main advantages of using sessions is the ability to persist certain parameters across multiple requests. For example, you can set common headers or authentication credentials that will be automatically included with every request made by the session.

Here’s an example of setting headers and making subsequent requests:

session.headers.update({'User-Agent': 'Mozilla/5.0'})
response1 = session.get('https://example.com')
response2 = session.get('https://example.com/another-endpoint')

In the above example, the user-agent header is set once on the session object, and it will be included with both requests.

Session Timeout

Sessions also allow you to control the timeout for all requests made by the session. This is useful when dealing with slow or unreliable connections.

Here’s an example of setting a timeout for the session:

session.timeout = 10  # Timeout in seconds
response = session.get('https://example.com')

In this example, the session will wait for a maximum of 10 seconds for the response to arrive. If the response does not arrive within the specified timeout, an exception will be raised.

Closing a Session

After you are done with a session, it’s a good practice to close it to free up any system resources it might be using. The easiest way to do this is by using the close() method on the session object.

Here’s an example of closing a session:

session.close()

It’s worth noting that sessions are not thread-safe and should not be shared across multiple threads. If you need to make concurrent requests, it’s recommended to use a separate session for each thread.

Conclusion

Using sessions with requests-html can greatly simplify your HTTP requests workflow. Sessions provide a convenient way to manage cookies, headers, timeouts, and other session-specific parameters. By leveraging sessions, you can make your code cleaner and more maintainable.

I hope this blog post has provided you with a good introduction to session management with requests-html in Python. Happy coding!