Under what circumstances might a web crawler be your means of obtaining data?

Crawler is the mainstream data collection method at present, and the available data are roughly as follows:

1. Pictures, texts and videos will crawl product reviews and various photo websites to obtain picture resources and comment texts.

2. As the raw data of machine learning and data mining, for example, if you want to build a recommendation system, you can grab more dimensions of data and build a better model.

3. Conduct market research and business analysis, search for high-quality answers and screen high-quality content; Search real estate website information, analyze the trend of housing prices, and analyze housing prices in different regions; Grab the job information on the recruitment website and analyze the talent demand and salary level of various industries.