Access behaviour for Explorer.DataFrame

[mooreryan]

Thanks for the responses josevalim and billylanchantin!!

@josevalim

The Explorer team has decided that it makes more sense to raise (catching errors early) than return nil.

That makes sense. I was not aware that the return types for a behaviour were flexible.

@josevalim

I’d have to put more thought into it but, in the face of the two conflicting positions below, I’d probably stick with the first one:

• We should let data structures decide what is best for them
• Access should impose it to return nil

This is interesting. I’m new to Elixir, so I can’t really say how it ought to be, but at least for me, the DataFrame implantation of Access being different from the Access docs was surprising. But that could be addressed by adding something to DataFrame docs.

@josevalim

the other functionality is made available through the Access module itself. It is similar to a GenServer, where you implement handle_call but you must invoke GenServer.call.

Thanks for the explanation. That makes sense.

@billylanchantin

You can also do:

df = Explorer.DataFrame.new(a: [1, 2, 3])

if "a" in df.names do
  # ...
end

Thanks, I will go with something like this for now.