Raymond Hettinger added the comment: > Would it be reasonable to develop a Python API for this?
I suspect that in pure Python, the overhead would exceed the benefit. Current code: d[key] = d[key] + 1 Effort to save a double hash: h = hash(key) c = d.getitem_known_hash(key, hash) d.setitem_known_hash(key, hash, c + 1) In PyPy, the second code sample might actually be faster that the first, but all the other pythons suffer from interpreter overhead, a double dict lookup for the hash() function, two dict lookups just to find the new methods, allocating a bound method, and forming two argument tuples. There is also an API design issue. The pure python core datatype APIs are designed in a way to encourage higher level thinking (that is why we can't directly manage hash table sparsity or list over-allocation for example). In contrast, the C API is aimed at users who seek additional control and optimization at a lower level than the core language provides. We tend to expose a number of tools at the C level that would be inappropriate for higher-level code. ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue21101> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
