Hi, it is a known bug that External Locations do not work for Azure Storage Account root locations. Please create a folder in the root location and use that as the external location.

With the External Location and its permissions properly set up, you are able to read its content into Spark dataframes using the URI ('abfss://...'). Databricks runtime supports the binary file data source.

Reading the file using the lines of code you provided (with open('abfss://...') as f: ...) is not supported yet.