To follow up on lightgreen's comment, in arijun's own linked-to URI they specifically mention the new level of indirection right away. Indirection is not "free

To follow up on lightgreen's comment, in arijun's own linked-to URI they specifically mention the new level of indirection right away. Indirection is not "free" at all. For very large dict()s in main memory/DRAM it could be 2X slower. A hot loop benchmark where the CPU can perfectly predict its near future work and its prefetcher can mask DRAM latency may not reveal this, but a less "simple" benchmark would. The primary point of the ordering feature (and insertion ordering) is because Python uses that very same dict implementation for language features such as keyword args {def foo(\\kwargs)}. Changing to hash-order from "source code"-order can be confusing.