Here are some powerful libraries related to Python crawlers:

1. BeautifulSoup: This is a Python library for extracting data from web pages. It can extract the structure of data from HTML or XML files and provides a simple interface so that you can use it very conveniently to crawl data.

2. Scrapy: This is a Python framework for crawling websites and extracting data. It provides many functions, including tracking links, executing JavaScript, extracting data, etc.

3. Selenium: Although it is mainly used for web automation testing, it can also be used for crawlers. Selenium can simulate real user behaviors, such as clicking buttons, entering text, etc., which is very useful in some cases.

4. Requests: This is a very popular Python HTTP library. It provides a simple and easy-to-use API to send HTTP requests, which is very useful for crawlers.

5. PyQuery: This is a jQuery-style HTML parser. With PyQuery, you can parse an HTML document into a DOM tree, and then use jQuery-like syntax to query and manipulate the tree.

6. lxml: This is an efficient HTML and XML parsing library. Its syntax is similar to BeautifulSoup, but its performance is generally better.

7.http.client: This is a module in the Python standard library for sending HTTP and HTTPS requests. Although its API may be more complex than some third-party libraries, its stability and built-in Python support are unmatched by some other libraries.

8.aiohttp: For crawlers that need to fetch a large number of web pages concurrently, aiohttp is a very good choice. This is an asynchronous IO-based HTTP library that can send HTTP requests very efficiently.

9.Portia: This is a visual crawler tool that allows you to create crawlers very conveniently. You only need to specify the web page you want to crawl, and Portia will automatically generate the code for crawling the web page for you.

10.Scrapinghub: This is a cloud crawler service that allows you to easily create and manage large-scale crawler projects.

These libraries are very commonly used and efficient libraries in Python crawler development. I hope it will be helpful to you!