In this section the presentation mentions " Another reason is, once you download a CSV file, it becomes a stable data source. This is unlike the one you fetch from web data sources. "
Can this be explained a little more?
Thank you
The stability refers to that availability of the data fetched from the CSV file compared to web sources. Since the CSV is stored in your local drive, it can be accessed without any dependence on the third party. Thus, a stable source to get data from. But in the case of web sources such as google finance or yahoo finance, the data fetching can fail if the third party web services are unavailable and they also impsoe limits on number of requests you can make.
We will update the description in the notebook. Thanks for the feedback.