First, at the start of the source code file, we see the Python imports:

...truncated...
import requests     # (1)

There is one specific import I want to draw your attention to. On line (1), we are importing the request module (this was installed earlier in this chapter when you ran pip install -r requirements.txt). requests is a high-level library for making HTTP requests in Python. Our program uses this module to communicate with the dweet.io APIs, which we'll see shortly.

Now that we understand that we are importing and will later use the requests library, let's cover the global variables used in our program.