foreword
Before recommending the Python crawler course, let's talk about these related concepts of crawlers.
what is a reptile
Web crawler: also known as web spider, web robot, is a program or script that automatically grabs information on the World Wide Web according to certain rules.
In the era of big data, to conduct data analysis, you must first have a data source, but where does the data source come from? If you spend money and have no budget, you can only grab it from other websites.
Subdivided, the industry is divided into two categories: crawlers and anti-crawlers.
Anti-crawler: As the name suggests, it is to prevent you from being a crawler on my website or APP.
A crawler engineer and an anti-crawler engineer are a pair of friends who love and kill each other. They often lose their jobs because the other party has to work overtime to write code. For example, the following picture, everyone feels it carefully:
[----Help Python learning, all the following learning materials are free at the end of the article! ----】
Fundamentals of reptiles
As shown in the figure above, the first step of the crawler is to request the webpage to be crawled to obtain the corresponding returned results, and then use some methods to analyze the response content and extract the desired content resources. Finally, the The extracted resources are saved.
Crawler tools and language selection
1. Reptile tool
I believe everyone knows the truth that if you want to do a good job, you must first sharpen your tools. If you want to improve efficiency, some commonly used tools are essential. The following are several tools that I personally recommend: Chrome, Charles, Postman, Xpath- Helper
2. Reptile language
At present, mainstream Java, Node.js, C#, python and other development languages can implement crawlers.
Therefore, in terms of language selection, you can choose the language you are best at to write crawler scripts.
At present, python is the most commonly used in crawlers, because python has a concise syntax and is easy to modify, and there are many crawler-related libraries in python, which can be used just by taking them, and there are more information on the Internet.
Reptile technical steps
The first step: crawling data, in fact, it is to initiate a network request to the server according to a URL, and obtain the data returned by the server
Step 2: Parse the data and convert the data returned by the server into a format that is easy for people to understand
The third step: filter the data, and filter out the required data from a large amount of data
Step 4: Store data, store the filtered and useful data, such as: database, CSV file, Excel file, JSON file, etc.
As long as the friends follow these four steps, it is still very simple to realize a crawler task.
After understanding this knowledge, it is recommended to follow the video to learn Python crawlers first. With a certain foundation, I recommend you to read some Python crawler books to check for gaps and fill in gaps for a deeper understanding ! Video + books are eaten together, the effect is better!
Finally, I will introduce a complete python learning route, from entry to advanced, including mind maps, classic books, and supporting videos, to help those who want to learn python and data analysis!
1. Introduction to Python
The following content is the basic knowledge necessary for all application directions of Python. If you want to do crawlers, data analysis or artificial intelligence, you must learn them first. Anything tall is built on primitive foundations. With a solid foundation, the road ahead will be more stable.
Include:
Computer Basics
python basics
Python introductory video 600 episodes:
Watching the zero-based learning video is the fastest and most effective way to learn. Following the teacher's ideas in the video, it is still very easy to get started from the basics to the in-depth.
2. Python crawler
As a popular direction, reptiles are a good choice whether it is a part-time job or as an auxiliary skill to improve work efficiency.
Relevant content can be collected through crawler technology, analyzed and deleted to get the information we really need.
This information collection, analysis and integration work can be applied in a wide range of fields. Whether it is life services, travel, financial investment, product market demand of various manufacturing industries, etc., crawler technology can be used to obtain more accurate and effective information. use.
Python crawler video material
3. Data analysis
According to the report "Digital Transformation of China's Economy: Talents and Employment" released by the School of Economics and Management of Tsinghua University, the gap in data analysis talents is expected to reach 2.3 million in 2025.
With such a big talent gap, data analysis is like a vast blue ocean! A starting salary of 10K is really commonplace.
4. Database and ETL data warehouse
Enterprises need to regularly transfer cold data from the business database and store it in a warehouse dedicated to storing historical data. Each department can provide unified data services based on its own business characteristics. This warehouse is a data warehouse.
The traditional data warehouse integration processing architecture is ETL, using the capabilities of the ETL platform, E = extract data from the source database, L = clean the data (data that does not conform to the rules), transform (different dimension and different granularity of the table according to business needs) calculation of different business rules), T = load the processed tables to the data warehouse incrementally, in full, and at different times.
5. Machine Learning
Machine learning is to learn part of the computer data, and then predict and judge other data.
At its core, machine learning is "using algorithms to parse data, learn from it, and then make decisions or predictions about new data." That is to say, a computer uses the obtained data to obtain a certain model, and then uses this model to make predictions. This process is somewhat similar to the human learning process. For example, people can predict new problems after obtaining certain experience.
Machine Learning Materials:
6. Advanced Python
From basic grammatical content, to a lot of in-depth advanced knowledge points, to understand programming language design, after learning here, you basically understand all the knowledge points from python entry to advanced.
At this point, you can basically meet the employment requirements of the company. If you still don’t know where to find interview materials and resume templates, I have also compiled a copy for you. It can really be said to be a systematic learning route for nanny and .
But learning programming is not achieved overnight, but requires long-term persistence and training. In organizing this learning route, I hope to make progress together with everyone, and I can review some technical points myself. Whether you are a novice in programming or an experienced programmer who needs to be advanced, I believe that everyone can gain something from it.
It can be achieved overnight, but requires long-term persistence and training. In organizing this learning route, I hope to make progress together with everyone, and I can review some technical points myself. Whether you are a novice in programming or an experienced programmer who needs to be advanced, I believe that everyone can gain something from it.
Data collection
This full version of the full set of Python learning materials has been uploaded to the official CSDN. If you need it, you can click the CSDN official certification WeChat card below to get it for free ↓↓↓ [Guaranteed 100% free]
Good article recommendation
Understand the prospect of python: https://blog.csdn.net/SpringJavaMyBatis/article/details/127194835
Learn about python's part-time sideline: https://blog.csdn.net/SpringJavaMyBatis/article/details/127196603
