On 2019年1月18日 03:00:54 +0000 MRAB <[email protected]> wrote: > On 2019年01月18日 00:48, Gregory P. Smith wrote: > > I've heard that libraries using ctypes, cffi, or cython code of various > > sorts in the real world wild today does abuse the unfortunate side > > effect of CPython's implementation of id(). I don't have specific > > instances of this in mind but trust what I've heard: that it is happening. > > > > id() should never be considered to be the PyObject*. In as much as code > > shouldn't assume it is running on top of a specific CPython implementation. > > If there is a _need_ to get a pointer to a C struct handle referencing a > > CPython C API PyObject, we should make an explicit API for that rather > > than the id() hack. That way code can be explicit about its need, and > > code that is just doing a funky form of identity tracking without using > > is and is not can continue using id() without triggering regressive > > behavior on VMs that don't have a CPython compatible PyObject under the > > hood by default. > > > > [who uses id() anyways?] > > > I use it in some of my code. > > If I want to cache some objects, I put them in a dict, using the id as > the key. If I wanted to locate an object in a cache and didn't have > id(), I'd have to do a linear search for it.
Indeed. I've used it for the same purpose in the past (identity-dict). Regards Antoine. _______________________________________________ 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