Crawler is a fun technology, see beautiful beauty can secretly climb to take mm photos, climb zhihu user profile picture and so on, these tutorial experience post on the Internet casually search, everywhere; So dodi technical instructor shows you how to get started with a Python crawler?
Python is so popular because it can do so many things, from the construction of a web page and a website to artificial intelligence, AI, big data analysis, machine learning, cloud computing and other cutting-edge technologies, all based on Python. Powerful programming language, you must find it difficult to learn. But in fact, Python is very easy to get started with.
Because it has a rich standard library, not only the language is simple and easy to understand, readable, the code also has a strong extensibility, compared with C language, Java and other programming languages to be much simpler. C might require 1,000 lines of code, Java might require several hundred lines, and Python might require only a few dozen. One of the most widely used Python scenarios is the crawler, which is why many newcomers to Python get started.
Web crawler is one of the simplest, most basic, and most useful techniques in Python. It is also very simple to write, and there is no need to learn how to render and generate web information. It is easy to write a crawler once you have mastered the basic syntax of Python. Despite all the “simplicity” above, it’s not easy to actually implement a commercially viable crawler. The code above can be used to climb an entire website with almost no problem.
The first step of web crawler is to obtain the HTML information of web page according to URL. In Python3, you can use urllib.request and requests for web page crawls. The urllib library is built into Python, so you don’t need to install it. You can use it if you have Python installed. The Requests library is a third-party library that we need to install ourselves.