In this blog post, we will explore how to analyze the resources on webpages using Python and the requests library. The requests library is a powerful tool for making HTTP requests and working with web resources. We will learn how to retrieve webpages, extract different types of resources such as images, CSS files, and JavaScript files, and perform basic analysis on them.

Installing requests

Before we get started, we need to make sure that the requests library is installed. If you haven’t installed it yet, you can do so by running the following command:

pip install requests

Retrieving a webpage

To begin our resource analysis, we first need to retrieve the webpage we want to analyze. We can use the get method from the requests library to make a GET request to the webpage URL. Here’s an example:

import requests

url = "https://www.example.com"
response = requests.get(url)

In the code above, we define the url variable with the URL of the webpage we want to retrieve. We then use the get method from requests to make the GET request and store the response in the response variable.

Extracting resources

Once we have retrieved the webpage, we can start extracting different types of resources from it. For example, to extract all the images on the webpage, we can use regular expressions or libraries like BeautifulSoup to parse the HTML and find the img tags. Here’s an example:

import re

pattern = r'<img.*?src="(.*?)".*?>'
images = re.findall(pattern, response.text)

In the above code, we define a regular expression pattern to match the src attribute of the img tag. We then use re.findall to find all occurrences of this pattern in the HTML of the webpage.

Similarly, we can extract other types of resources like CSS files and JavaScript files by modifying the regular expression pattern or using appropriate parsing libraries.

Analyzing resources

Once we have extracted the resources, we can perform various analysis on them. For example, we can count the number of resources, calculate the sizes of the resources, or identify any broken links.

Here’s an example of calculating the total size of all the images:

total_size = 0

for image in images:
    image_response = requests.get(image)
    total_size += len(image_response.content)

print("Total size of images:", total_size)

In the code above, we loop through each image URL, make a GET request to retrieve the image, and calculate the size of the image by getting the length of the response content. We then accumulate the sizes to get the total size of all the images.

Conclusion

In this blog post, we have learned how to analyze the resources on webpages using Python and the requests library. We covered how to retrieve a webpage, extract different types of resources like images, CSS files, and JavaScript files, and perform basic analysis on them. With these techniques, you can gather valuable insights about the resources used on a webpage and optimize their usage for better performance.

Happy analyzing!