As we all know, almost every programming language can implement a crawler, such as Java, C, C++, python, etc., but we chose python to write a crawler because of its unique advantages. So what are the advantages of using python language to write crawlers? Let's take a look at the detailed content.

The scripting features of python are easy to configure and flexible to handle characters. In addition, python has rich network capture modules, so the two are often connected.

As a programming language, python is pure free software, which is popular with programmers because of its concise and clear syntax and the mandatory use of white space for sentence indentation. If you use python to complete the programming task, you will write less code, and the code is concise, short and readable. When a team is developing, it will read others' code faster, and the development efficiency will be higher, making the work more efficient.

This is a programming language very suitable for developing web crawlers. Compared with other static programming languages, python's interface for capturing web documents is more concise; Compared with other dynamic scripting languages, python's urllib2 package provides a more complete API for accessing web documents. In addition, there are excellent third-party packages in python that can efficiently achieve web page crawling, and can complete the tag filtering function of web pages with extremely short code. This is why python is called a crawler.

What is python crawler?

A crawler, that is, a web crawler, can be understood as a spider crawling on the web. The internet is like a big web. A crawler is a spider crawling around on this web. If it meets its prey, it will catch it. For example, it is crawling a web page. In this web page, it has found a path, which is actually a hyperlink to the web page. Then it can crawl to another web page to obtain data.

What are the advantages of writing crawlers in python?

1.Grab the interface of the page itself

Compared with other static programming languages, such as Java, C #, C++, python's interface for capturing web documents is more concise; Compared with other dynamic scripting languages, such as perl and shell, python's urllib2 package provides a more complete API for accessing web documents.

In addition, crawling web pages sometimes needs to simulate the behavior of browsers, and many websites are blocked from rigid crawler crawling. At this time, we need to simulate the behavior of useragent to construct appropriate requests, such as simulating user login, simulating the storage and setting of session/cookie. In python, there are excellent third-party packages to help you deal with, such as Requests and mechanize.

2.Processing after web page capture

The captured web pages usually need to be processed, such as filtering html tags, extracting text, etc. Python's beautiful soap provides concise document processing functions, and can complete most document processing with extremely short code. In fact, many languages and tools can do the above functions, but python can do the fastest and cleanest.