[issue13965] Windows 64-bit installer actually installing a 32-bit version

Raymond Hettinger added the comment: Martin, thanks for the explanation. Hopefully, this tracker entry will serve to permanently document why Python2 on Windows behaves as it does. -- ___ Python tracker

[issue13965] Windows 64-bit installer actually installing a 32-bit version

Martin v. Löwis added the comment: On Win64, the long type is 32-bit; the compiler does not support any other mode. So the question "whether another memory model could have been selected during compilation" must be answered as "no, the compiler does not support multiple memory models". We co

[issue13965] Windows 64-bit installer actually installing a 32-bit version

Amaury Forgeot d'Arc added the comment: LLP64 is the model chosen by the Microsoft compiler: sizeof(long)==4. I suppose someone already considered to change PyIntObject and use size_t values, but IMO it would have broken too many extensions: the pattern "if (PyInt_Check(obj)) value=PyInt_AS_L

[issue13965] Windows 64-bit installer actually installing a 32-bit version

Raymond Hettinger added the comment: platform.architecture() and struct.calcsize("P") confirm that this build used 64-bits for pointers and 32-bits for ints. This leaves the question of whether LLP64 is required to run Python on Windows or whether another memory model could have been selected

[issue13965] Windows 64-bit installer actually installing a 32-bit version

Ralf Schmitt added the comment: according to the documentation platform.architecture() may not work on OS X. -- ___ Python tracker ___ __

[issue13965] Windows 64-bit installer actually installing a 32-bit version

Ralf Schmitt added the comment: struct.calcsize("P")==8 will tell you if you're running a 64bit python or not. -- nosy: +schmir ___ Python tracker ___ __

[issue13965] Windows 64-bit installer actually installing a 32-bit version

Mark Dickinson added the comment: Or more directly, try platform.architecture(). -- nosy: +mark.dickinson ___ Python tracker ___ ___

[issue13965] Windows 64-bit installer actually installing a 32-bit version

Amaury Forgeot d'Arc added the comment: IIRC sys.maxsize was added for this reason. This one should show a 64bit value. -- nosy: +amaury.forgeotdarc ___ Python tracker ___ _

[issue13965] Windows 64-bit installer actually installing a 32-bit version

Nadeem Vawda added the comment: 64-bit Windows (or at least Visual C++) uses the LLP64 model, so a long is 32 bits wide (the only 64-bit integer type being long long) - see Since Python's int is documented as being implemented on top of C

[issue13965] Windows 64-bit installer actually installing a 32-bit version

New submission from Raymond Hettinger : On the downloader page, http://www.python.org/download/releases/2.7.2/ there is an entry "•Windows X86-64 MSI Installer" that links to http://www.python.org/ftp/python/2.7.2/python-2.7.2.amd64.msi Running this installer succeeds and show messages that a