Shekhar Prasad Rajak

Thanks! I think for 1st example v2 will be good. For 2nd example: I think, it should allow repeating index values. Means in 2nd example `df ` must be :...

I think if if indexes are not unique then `Daru::Index` must automatically go to the `Daru::CategoricalIndex` like how `Daru::Index` returns `Daru::MultiIndex` when tuples are passed. Means ``` irb(main):012:0> Daru::Index.new([1,2,3]) =>...

I am using Categorical Index when there is only one level and labels left (and duplicate index present), see : https://github.com/SciRuby/daru/pull/340/files#diff-df0c816a5a6b82ab4d961bf9d1a0acbfR248

@bruzos , can you please paste all the related sample code. Means what is `data` vector.

Yes! There should be `begin`, `rescue` block to handle any kind of error coming from another gem. It must throw an error with the correct input type.

We can have a custom error class for daru library.

> `[]=` `add_vector` does not specify the insertion location. Can you please elaborate a bit this line?

This is good point. we can add another column easily but then we have to order it. You can also do `df[:player] = df.index` but yeah we should have a...

Thanks for letting us know this usecase.

@cyrillefr , please go ahead. You can discuss your approach here once so that we can verify that you are going in right way then you can open a PR.