[aaronbee]

Here’s a description of the new map implementation and why it’s more efficient: https://www.pypy.org/posts/2015/01/faster-more-memory-effici...

[adgjlsfhk1]

Note that this applies more for python than efficient languages. In python, objects are big, and require an indirection. In faster languages, many objects can be smaller than a pointer and stored inline. As such, dictionaries that have vectorized lookups generally can be made faster.