In the tutorial at https://stravalib.readthedocs.io/en/v2.2/get-started/how-to-get-strava-data-python.html in the bottom part of Step 1

it seems like you should save your client secret and access token in the txt file. When we are loading the tokes in

client_id, access_token = open("client_secrets.txt").read().strip().split(",")

we read the client id and the access token, which is what we need later in the tutorial. So the text in the tutorial includes an error and should be changed to client id everywhere where secret value is mentioned.