How to write a complete crawler framework

This article mainly shares with you how to completely write a request method for a crawler framework. It has a good reference value and I hope it will be helpful to everyone. Let’s follow the editor to take a look, I hope it can help everyone.

Generate crawler framework:

1. Create a scrapy crawler project

2. Generate a scrapy crawler in the project

3. Configure the spider crawler

4. Run the crawler to obtain the web page

Specific operations:

1. Create a project

Define a project with the name: python123demo

Method:

In cmd, d: Enter the d drive, cd pycodes Enter the file pycodes

Then enter

scrapy startproject python123demo

A file will be generated in pycodes:

##_init_.py does not require user writing

2. Generate a scrapy crawler in the project

Execute a command to Output the name of the crawler and the crawled website

Generate the crawler:

Generate a name Spider

for demo can only generate demo.py, its content is:

name = 'demo' The current crawler name is demo

allowed_domains = " Crawl the links below the domain name of the website. The domain name is entered from the cmd command console

start_urls = [] The initial page to be crawled

parse() is used to process the response, parse the content to form a dictionary, and discover new url crawling requests

3. Configure the generated spider crawler to meet our needs

Save the parsed page into a file

Modify the demo.py file

##4. Run the crawler to get the web page

Open cmd and enter the command line to crawl

Then it appeared on my computer An error

The solution to this problem on the windows system requires the installation of the Py32Win module, but installing the exe directly through the official website link will cause hundreds of errors. An error, a more convenient way is

#pip3 install pypiwin32

This is the solution for py3

Note: If you use the pip install pypiwin32 command for the py3 version, an error will occur

After the installation is completed, Run the crawler again, success! Throw flowers!

The captured page is stored in the demo.html file

##The complete code corresponding to demo.py:

The two versions are equivalent:

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