How to figure out if the platform is 32bit or 64bit?

[Fredrik Lundh]

Ken Hartling wrote:

 > Thanks .. but I want to find out if the system is "running on 64bit"
 > even when the interpreter is a 32-bit build executable ("what python
 > was built on").  platform.architecture() and platform() in general
 > seems to only be looking at the build executable

You can pass in an arbitrary binary to architecture(), so I guess you 
could use this on some suitable thing under "/bin" on a Unix box.  This 
doesn't work on Windows, though.

In this message,

     http://mail.python.org/pipermail/python-list/2005-June/326158.html

Thomas Heller suggests using ctypes to call the Windows API directly; so 
something like this could work:

 >>> import ctypes, sys
 >>> i = ctypes.c_int()
 >>> kernel32 = ctypes.windll.kernel32
 >>> process = kernel32.GetCurrentProcess()
 >>> kernel32.IsWow64Process(process, ctypes.byref(i))
1
 >>> is64bit = (i.value != 0)
 >>> is64bit
False

(IsWow64Process returns a non-zero value if it manages to check the 
status, and sets the variable to a non-zero value if the process is 
running under WOW64.  I only have 32-bit boxes here, so it's only 
partially tested).

And yes, looks like official support for this might appear in 2.6:

http://mail.python.org/pipermail/python-dev/2008-May/079022.html

(in that thread, Mark Hammond suggests "'64 bit' in sys.version" as a 
workaround, but warns for false negatives).

</F>