AVL Tree [Python]

[avsingh999]

This issue is about [Algo/DS Name](link to resource for the Algo/DS).

• [x] Issue Title is in form Algo/DS Name [Language].
• [x] I searched or browsed the repo’s other issues to ensure this is not a duplicate.
• [x] This Algo/DS is worth adding to this repository.
• [x] Assign this issue to me (I want to work on this).
  • [x] I ensure that I am not already assigned to 2 or more issues.
• [x] I will send my PR only after I'm assigned to this issue by any maintainer.
• [x] I understand that I will be unassigned from this issue if I fail to send a PR for this within a week.

[singhpratyush]

The contributors most likely able to help are:

@Monal5031

Possible duplicate or related issues are:

• #345: Gradient Descent [Python]
• #428: Add badges to README.md
• #391: Shell Sort [Java]
• #478: Algo/largest_sum_contiguous_subarray [C++]
• #547: Binary Search Tree [Python]

[Jatin-Goyal-552]

Sir,I want to work on this issue.