Table of contents
In this blog, we will learn how to get video information and download link from a video sharing website. We will write a simple web crawler using Python to get information such as title, description, thumbnail and download link of a video. In this case, but the method is equally applicable to other video sharing sites.
Note : Before you begin, make sure you have complied with the terms of use and policies of the site in question. Web crawlers may put pressure on the server of the website, please ensure that your actions are legal and compliant.
Table of contents
- Preparation
- Analyze web page structure
- Write a crawler
- Extract video information
- Get video download link
- Test and optimize
- Summarize
1. Preparations
Before we start writing our crawlers, we need to install some Python libraries. These libraries will help us implement network requests, parse HTML and JSON data more easily. Please make sure you have installed the following libraries:
requests: Used to send HTTP requestsBeautifulSoup: for parsing HTMLpytube: Used to parse download links of YouTube videos
You can install these libraries with the following commands:
pip install requests beautifulsoup4 pytube2. Analyze web page structure
Before writing a crawler, we need to analyze the structure of the target webpage to understand how to extract the required information. Open YouTube and search for a keyword, such as "Python tutorial". Then view the source code of the web page to find the HTML element that contains the video information. Typically, video information is contained within an element named "item-section" <div>.
For example, we might find the following HTML code:
<div class="item-section">
<ul>
<li>
<div class="yt-lockup-dismissable">
<div class="yt-lockup-thumbnail">
<a href="/watch?v=abcd1234">
<img src="https://example.com/thumbnail.jpg">
</a>
</div>
<div class="yt-lockup-content">
<a href="/watch?v=abcd1234" class="yt-lockup-title">
Python教程 - 学习Python编程
</a>
<div class="yt-lockup-description">
本教程将教你如何使用Python编程。适用于初学者和有经验的开发者。
</div>
</div>
</div>
</li>
...
</ul>
</div>We can see that the title, description, thumbnail and link of the video are all contained in this HTML structure. Next, we'll use this information to write a crawler.
3. Write a crawler
We will use requeststhe library to send HTTP requests to get the content of the web page. Then, using BeautifulSoupthe parsed HTML, the video information is extracted. The following is a simple crawler code:
import requests
from bs4 import BeautifulSoup
def get_search_results(query):
url = f"https://www.youtube.com/results?search_query={query}"
response = requests.get(url)
soup = BeautifulSoup(response.text, "html.parser")
return soup.find_all("div", class_="yt-lockup-dismissable")
query = "Python教程"
results = get_search_results(query)
for result in results:
print(result.prettify())This code outputs the HTML code for each video on the search results page. Next, we will extract the details of each video.
4. Extract video information
We'll write a extract_video_infofunction called , which extracts the title, description, thumbnail, and link for each video. Here is the code for the function:
def extract_video_info(video_element):
title_element = video_element.find("a", class_="yt-lockup-title")
title = title_element.text
url = "https://www.youtube.com" + title_element["href"]
description_element = video_element.find("div", class_="yt-lockup-description")
description = description_element.text if description_element else ""
thumbnail_element = video_element.find("img")
thumbnail = thumbnail_element["src"] if thumbnail_element else ""
return {
"title": title,
"url": url,
"description": description,
"thumbnail": thumbnail
}
# 在前面的代码中添加此函数，并修改循环以提取视频信息
for result in results:
video_info = extract_video_info(result)
print(video_info)This code will output the title, description, thumbnail and link for each video. Now, we need to get the download link for the video.
5. Get video download link
In order to get the download link of the video we will use pytubethe library. This library provides a simple API to get download links for videos in various formats and qualities based on the video URL. Here is a get_video_download_linkfunction called to get the download link of a video:
from pytube import YouTube
def get_video_download_link(url):
try:
yt = YouTube(url)
stream = yt.streams.filter(progressive=True).first()
return stream.url if stream else ""
except Exception as e:
print(f"Error getting download link: {e}")
return ""
# 在前面的代码中添加此函数，并修改循环以获取视频下载链接
for result in results:
video_info = extract_video_info(result)
download_link = get_video_download_link(video_info["url"])
print(f"{video_info['title']} ({video_info['url']}) - Download link: {download_link}")This code will output the title, link and download link for each video. Note that this function may fail for various reasons such as request throttling or website changes. In this case it will return an empty string.
6. Testing and optimization
Now, our crawler is complete. You can test and optimize it as needed. For example, you can add error handling and retry logic to make your crawler more robust. You can also try to use multi-threading or asynchronous requests to increase the speed of the crawler. Additionally, you can modify the crawler as needed to obtain additional information such as author name, publication date, etc.
7. Summary
In this blog, we learned how to obtain video information and download links from a video sharing website (Take YouTube as an example). We wrote a simple web crawler in Python to get information like title, description, thumbnail and download link of a video. This method can be easily applied to other video sharing sites, just modify the URL and HTML selector.
Remember that web crawlers can put a strain on a website's servers, so make sure you're doing it legally and compliantly. In practice, please follow the terms of use and policies of the relevant websites.