Parameter to call

[matham]

Generally, a function should not return different types of things depending on a argument passed to it. Instead, it's generally preferable to split it into 2 functions. Matplotlib violates this a lot and returns different things based on the input and it's annoying af.

If we need __call__ to return the combinations, I'd suggest we only return that and have a different method e.g. get_data_frame that returns a data frame when called. Although I'm not sure we should use pandas so much in the codebase because there are downsides to making that a dependency of the framework.

Originally posted by @matham in #1 (comment)