Sending a HEAD HTTP Request in Python 2: A Beginner's Guide
When it comes to making HTTP requests in Python, the most commonly used library is the urllib2 module. This module provides a simple interface for fetching data from URLs and sending HTTP requests. However, while urllib2 is great for most situations, there may be times when you need more control over the type of request you are sending. In this article, we will discuss how to send a HEAD HTTP request in Python 2 using the built-in httplib module.
Before we dive into the details, let's first understand what a HEAD request is and when it is useful. In simple terms, a HEAD request is a type of HTTP request that only retrieves the headers of a response, without actually downloading the content of the response. This can be useful when you only need to check the status or header information of a resource, without the need to download the entire content. It can also save bandwidth and improve performance, especially when dealing with large files.
Now, let's get started with the code. First, we need to import the httplib module, which is part of the standard library in Python 2. Then, we will create an instance of the HTTPConnection class, passing in the URL of the resource we want to make the request to. For this example, let's use the URL of a website's homepage:
```
import httplib
conn = httplib.HTTPConnection("www.example.com")
```
Next, we need to specify the type of request we want to send. In this case, we want to send a HEAD request. We can do this by calling the request() method on the connection object, passing in the method name as the first parameter and the path of the resource as the second parameter. Since we want to retrieve the headers of the homepage, we will pass in an empty string as the path:
```
conn.request("HEAD", "")
```
Now, we can retrieve the response from the server by calling the getresponse() method on the connection object. This will return an HTTPResponse object, which contains the status code, headers, and any other information related to the response. To access the headers, we can use the getheaders() method on the HTTPResponse object, which will return a list of tuples containing the header names and their corresponding values. For example, to print the content-type header, we can use the following code:
```
response = conn.getresponse()
headers = response.getheaders()
print "Content-Type:", dict(headers)["content-type"]
```
Finally, we need to close the connection to release any resources used by the connection. We can do this by calling the close() method on the connection object:
```
conn.close()
```
And that's it! We have successfully sent a HEAD HTTP request and retrieved the headers of the homepage. Of course, you can also use this method to retrieve the headers of any other resource, as long as you provide the correct URL and path.
In conclusion, sending a HEAD HTTP request in Python 2 is a simple process that can be achieved using the built-in httplib module. With a few lines of code, you can retrieve the headers of a resource without having to download the entire content. This can be useful in various situations, such as checking the status of a website or retrieving metadata from a file. So go ahead and give it a try in your own projects. Happy coding!
