What does this python code mean?

Grab a web link?

Air quality index query (AQI)-PM2.5 query

It is to store the useful information in this website locally, and you can see the control quality of a city, such as PM2.5 in the picture.

This technology is called reptile. Very useful. As for what's in it:

Initiate a request

Processing data after receiving a response

save data