Relevant to some coding questions (like Facebook) that emphasize big-O.
— vector — The default list is a vector, with constant time random access.
Just like std::vector, deleting from beginning is slow, according to https://stackoverflow.com/questions/19441488/efficiency-of-len-and-pop-in-python
— fixed array — https://stackoverflow.com/questions/176011/python-list-vs-array-when-to-use shows array type is rarely needed.
— tree map — not popular
https://github.com/tiger40490/repo1/blob/py1/py/tree/simpleBST.py is my own BST without self-balancing.