binary-search-tree: implement exercise

[ilya-khadykin]

There are exercises that are not yet implemented in Python track (the full list of them - #417 (comment)).
You can help us change this situation by implementing this one. Ref #417

The guide "Implement an exercise from specification" will help you succeed.

If you still have questions, I encourage you to ask them before starting working on the issue.

I also suggest claiming the issue by creating an empty PR as stated here

Please note that there are some special 'closing issue' keywords that you can put in description of your PR and Github will take care of closing the corresponding issue automatically after merge.
This simple thing helps us a lot, and makes our life a bit easier

[ilya-khadykin]

#388 can be useful

[rodrigocam]

I'm working on it!

[ilya-khadykin]

@rodrigocam, I suggest creating an empty [WIP] PR - https://github.com/exercism/docs/blob/master/you-can-help/implement-an-exercise-from-specification.md#avoiding-duplicate-work to claim it

[ilya-khadykin]

@rodrigocam ah, I see, you've done that, but forgot to add a reference to this issue in order to add visibility. I strongly recommend always doing it, it saves a lot of time.

Please also note that there are some special 'closing issue' keywords that you can put in description of your PR and Github will take care of closing the corresponding issue automatically after merge.
It makes our work much easier. I hope this hint will help you to make your future PRs a bit better

[rodrigocam]

Alright, thanks! Which methods do you want in the binary search tree? I create an insert method and preorder, inorder and postorder traversals.

[rodrigocam]

I made a pull request with the implementation, please take a look!

[ilya-khadykin]

@rodrigocam thanks! You've created two PRs #773 and #768. Could you please close one to avoid confusion.

Which methods do you want in the binary search tree?

It's up to you

[rodrigocam]

Ok, sorry. I closed one of them, please take a look (: