Python can be used to write crawler programs under Linux. Commonly used crawler frameworks include Scrapy and BeautifulSoup.
Scrapy is a Python-based open source web crawler framework that can quickly and efficiently obtain data from websites. It provides powerful data extraction and processing functions, and supports features such as asynchronous network requests and distributed crawling.
BeautifulSoup is a Python library that can extract data from HTML or XML files. It supports a variety of parsers, which can easily process tags and attributes in web pages and extract the required data.
After installing Python and related libraries under Linux, you can use the command line or an editor to write a crawler program, and run the program to start crawling data. It should be noted that the crawler program must abide by the crawling rules of the website, and must not cause an excessive burden on the website or infringe on the legitimate rights and interests of the website.
To play through Linux, programmers need to master the following knowledge:
1. Command line operation
Linux is a command-line-based operating system. Programmers need to master basic command-line operations, such as file operations, process management, and network configuration.
2. Shell script programming
Shell script is a commonly used automation tool under Linux. Programmers need to master Shell script programming so that they can quickly write scripts to complete some repetitive tasks.
3. Network configuration
Programmers need to master the network configuration under Linux, including IP address, gateway, DNS, etc.
4. Software installation and configuration
There are many open source software available under Linux, programmers need to know how to install and configure these software.
5. System management
Programmers need to master system management under Linux, including user management, authority management, log management, etc.
6. Debugging and troubleshooting
Programmers need to master how to debug and troubleshoot Linux systems, including viewing logs and analyzing processes, etc.
Generally speaking, to play with Linux, programmers need to continue to learn and practice, master basic command line operation and system management skills, and also need to understand open source software and tools under Linux in order to be able to complete the work better.
Write a crawler for Linux
The following is a simple crawler for crawling web content written under Linux using Python:
Install Python and the requests module
Python is usually pre-installed in Linux, run the following command in the terminal to check the version of Python:
python --version
Install the requests module:
pip install requests
Write code
Create a new Python file under Linux, for example spider.py:
import requests
url = 'http://www.example.com'
response = requests.get(url)
if response.status_code == 200:
content = response.text
# 接下来可以进行数据处理或保存等操作
else:
print('访问失败: %d' % response.status_code)
The above code uses the requests library to request the specified URL, and processes and saves the data according to the returned result.
run code
Run the code with the following command in a terminal:
python spider.py
After execution, the program will automatically access the specified URL and output the response content, or prompt the status code of access failure.