You are able to set and get environment variables in Python you can just use the os module. 

import os
os.environ["VARIABLE_NAME"] = "variable value"

To get the value of an environment variable, use the os.environ.get() method:
import os
variable_value = os.environ.get("VARIABLE_NAME")

This will return the value of the environment variable if it exists, or None if it does not.

You can also use os.environ["VARIABLE_NAME"] directly but it will raise keyerror if the variable does not exist.