The expanded method help makes this clearer. You pass in a list that contains dictionaries, one dictionary per folder connection. Each dictionary has three keys and associated values: "connectionString" (A local or UNC path to a system folder), "alias" (optional alias for the path in the catalog view) and "isHomeFolder" (True if this entry is for the home folder, False otherwise). Basically you're passing in an anonymous config object like it's a JavaScript function, even though Python supports named objects. Guess whoever wrote that interface had a long day and didn't want to define a proper object 😁.