How do I determine if my python shell is executing in 32bit or 64bit?

Question

I need a way to tell what mode the shell is in from within the shell.

While I\'m primarily an OS X user, I\'d be interested in knowing about other platforms as well.<

Answer 1

platform.architecture() notes say:

Note: On Mac OS X (and perhaps other platforms), executable files may be universal files containing multiple architectures.

To get at the “64-bitness” of the current interpreter, it is more reliable to query the sys.maxsize attribute:

import sys
is_64bits = sys.maxsize > 2**32

Answer 2

struct.calcsize("P") returns size of the bytes required to store a single pointer. On a 32-bit system, it would return 4 bytes. On a 64-bit system, it would return 8 bytes.

So the following would return 32 if you're running 32-bit python and 64 if you're running 64-bit python:

Python 2

import struct;print struct.calcsize("P") * 8

Python 3

import struct;print(struct.calcsize("P") * 8)

Answer 3

Basically a variant on Matthew Marshall's answer (with struct from the std.library):

import struct
print struct.calcsize("P") * 8

Answer 4

For a non-programmatic solution, look in the Activity Monitor. It lists the architecture of 64-bit processes as “Intel (64-bit)”.

Answer 5

Open python console:

import platform
platform.architecture()[0]

it should display the '64bit' or '32bit' according to your platform.

Alternatively( in case of OS X binaries ):

import sys
sys.maxsize > 2**32 
# it should display True in case of 64bit and False in case of 32bit

Answer 6

Do a python -VV in the command line. It should return the version.