What is a User-Agent Header in Python Request?

The user agent is a key component of the HTTP header sent with every HTTP request. The User-Agent header is one of many standard request headers. These headers contain information the server uses to generate its response, such as the preferred content format and language. It identifies the requester’s device including information about the device type, operating system, browser name, and version. For example, The User Agent String Looks like this

"Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/123.0.0.0 Safari/537.36"
or 
"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.212 Safari/537.36'"

• Application (Mozilla/5.0): This identifies the application making the request, which in this case is a generic application using the Mozilla compatibility standard.
• Operating System (Macintosh; Intel Mac OS X 10.15.7): This specifies the operating system the user is running, which is macOS Catalina (version 10.15.7).
• Layout Engine (AppleWebKit/537.36): This indicates the layout engine used to render web pages, which here is AppleWebKit.
• Browser Engine (KHTML, like Gecko): This specifies the underlying browser engine that powers the layout engine. Here, it indicates KHTML (Kranberry HTML) which is the original rendering engine used in Safari. It also mentions “like Gecko” for compatibility purposes, signifying it adheres to the Gecko engine’s standards used by Firefox.
• Version (Chrome/123.0.0.0): This reveals the version of the browser being used, which is Chrome 123.0.0.0.
• Additional Info (Safari/537.36-Let’s): This part contains additional information specific to the browser. Here, “Safari/537.36” indicates the version of Safari the browser is compatible with, and “Let’s” seems to be a custom addition that might not have a standard meaning.

The User-Agent (UA) string is one of the most important factors in website identification in Web Scraping. It is like a fingerprint that a client or targeted website can identify. With the help of this, you can retrieve the data by shuffling the user agent into Python requests. It typically includes information about the software, operating system, and sometimes additional details such as the device type or version numbers. In this article, we will explain User Agent in Python Request.