Lesson 1 Preparation

The first lesson preparation

（ With https://movie.douban.com/top250 For example ）

One 、 Find web address ：

https://movie.douban.com/top250

Links to each page :url = ‘https://movie.douban.com/top250?start=’+ str(page*25)+’&filter=’(page It's the number of pages -1)

Two 、 Find the location of the data :

Method 1： Elements （element）

1.Fn+F12

2. Click on [ Failed to transfer the external chain picture , The origin station may have anti-theft chain mechanism , It is suggested to save the pictures and upload them directly (img-h9bUCdiE-1644636543579)(C:\Users\ litchi \Desktop\11.png)]

3. Click on the page content ：

[ Failed to transfer the external chain picture , The origin station may have anti-theft chain mechanism , It is suggested to save the pictures and upload them directly (img-oHpzYn7I-1644636543582)(C:\Users\ litchi \AppData\Roaming\Typora\typora-user-images\image-20220204143802608.png)]

We according to the Hierarchical structure Determine the data location ：

[ Failed to transfer the external chain picture , The origin station may have anti-theft chain mechanism , It is suggested to save the pictures and upload them directly (img-uAuwQR4t-1644636543582)(C:\Users\ litchi \Desktop\11.png)]

Method 2： The Internet （network）

headers： The request we sent

response： Request returned

3、 ... and 、 Coding standards

commonly python The first line of the program is to add ( In this way, Chinese... Can be included in the code )

#-*-coding:utf-8-*-
 perhaps 
#coding=utf-8

Used to test the program ：（ Define program entry ）

def main():
    print("hello")
if__name__=="__main__":# The underline has two , Call the function when the program executes 
    main()

Four 、 Introduce modules

Introduce your own modules ：

[ Failed to transfer the external chain picture , The origin station may have anti-theft chain mechanism , It is suggested to save the pictures and upload them directly (img-Z8aUO9Xg-1644636543583)(C:\Users\ litchi \AppData\Roaming\Typora\typora-user-images\image-20220204150503347.png)]

Modules introduced into the system ：

1. Installation Library ：

Method 1：

Click on Terminal

pip install Library name

eg:pip bs4

Method 2：

File->settings->Project douban->Project Intrpreter->±> Search for packages to install ->Install Package

2. Code

from bs4 import BeautifulSoup # Web page parsing , get data beautifulsoup4
import re # Regular expressions , Text matching 
import urllib.request,urllib.error # Appoint URL, Get web data 
import xlwt # Conduct excel operation 
import sqlite3 # Conduct SQLite Database operation 

t,urllib.error # Appoint URL, Get web data
import xlwt # Conduct excel operation
import sqlite3 # Conduct SQLite Database operation