2015年12月17日 23:17 GMT+01:00 Andrew Barnert via Python-Dev <[email protected]>: > Builtins do two dict lookups. > > So, the only thing you can optimize there is builtins. But maybe that's worth > it.
FYI I implemented an optimization in FAT Python to avoid lookups for builtin functions, builtin functions are copied to code constants at runtime: https://faster-cpython.readthedocs.org/fat_python.html#copy-builtin-functions-to-constants It's nothing new, it's the generalization of common hacks, like 'def func(len=len): return len(3)'. The optimization is restricted to loading builtin symbols which are not expected to be modified ;-) (Right now the optimization is disabled by default, because the optimizer is unable to detect when builtins are modified in the current function, and so it breaks the Python semantic.) > Class attributes (including normal methods, @property, etc.) do two or more > dict lookups--first the instance, then the class, then each class on the > class's MRO. Note: Types have an efficient cache for name lookups ;-) Thanks for this cache, it's no more an issue to have a deep hierarchy of classes. Victor _______________________________________________ Python-Dev mailing list [email protected] https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com