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Detect if Python script is running in focus [duplicate]

I would like to get the active window on the screen using python.
For example, the management interface of the router where you enter the username and password as admin
That admin interface is what I want to capture using python to automate the entry of username and password.
What imports would I require in order to do this?

On windows, you can use the python for windows extensions (http://sourceforge.net/projects/pywin32/):
from win32gui import GetWindowText, GetForegroundWindow
print GetWindowText(GetForegroundWindow())
Below code is for python 3:
from win32gui import GetWindowText, GetForegroundWindow
print(GetWindowText(GetForegroundWindow()))
(Found this on http://scott.sherrillmix.com/blog/programmer/active-window-logger/)

Thanks goes to the answer by Nuno André, who showed how to use ctypes to interact with Windows APIs. I have written an example implementation using his hints.
The ctypes library is included with Python since v2.5, which means that almost every user has it. And it's a way cleaner interface than old and dead libraries like win32gui (last updated in 2017 as of this writing). ((Update in late 2020: The dead win32gui library has come back to life with a rename to pywin32, so if you want a maintained library, it's now a valid option again. But that library is 6% slower than my code.))
Documentation is here: https://docs.python.org/3/library/ctypes.html (You must read its usage help if you wanna write your own code, otherwise you can cause segmentation fault crashes, hehe.)
Basically, ctypes includes bindings for the most common Windows DLLs. Here is how you can retrieve the title of the foreground window in pure Python, with no external libraries needed! Just the built-in ctypes! :-)
The coolest thing about ctypes is that you can Google any Windows API for anything you need, and if you want to use it, you can do it via ctypes!
Python 3 Code:
from typing import Optional
from ctypes import wintypes, windll, create_unicode_buffer
def getForegroundWindowTitle() -> Optional[str]:
hWnd = windll.user32.GetForegroundWindow()
length = windll.user32.GetWindowTextLengthW(hWnd)
buf = create_unicode_buffer(length + 1)
windll.user32.GetWindowTextW(hWnd, buf, length + 1)
# 1-liner alternative: return buf.value if buf.value else None
if buf.value:
return buf.value
else:
return None
Performance is extremely good: 0.01 MILLISECONDS on my computer (0.00001 seconds).
Will also work on Python 2 with very minor changes. If you're on Python 2, I think you only have to remove the type annotations (from typing import Optional and -> Optional[str]). :-)
Enjoy!
Win32 Technical Explanations:
The length variable is the length of the actual text in UTF-16 (Windows Wide "Unicode") CHARACTERS. (It is NOT the number of BYTES.) We have to add + 1 to add room for the null terminator at the end of C-style strings. If we don't do that, we would not have enough space in the buffer to fit the final real character of the actual text, and Windows would truncate the returned string (it does that to ensure that it fits the super important final string Null-terminator).
The create_unicode_buffer function allocates room for that many UTF-16 CHARACTERS.
Most (or all? always read Microsoft's MSDN docs!) Windows APIs related to Unicode text take the buffer length as CHARACTERS, NOT as bytes.
Also look closely at the function calls. Some end in W (such as GetWindowTextLengthW). This stands for "Wide string", which is the Windows name for Unicode strings. It's very important that you do those W calls to get proper Unicode strings (with international character support).
PS: Windows has been using Unicode for a long time. I know for a fact that Windows 10 is fully Unicode and only wants the W function calls. I don't know the exact cutoff date when older versions of Windows used other multi-byte string formats, but I think it was before Windows Vista, and who cares? Old Windows versions (even 7 and 8.1) are dead and unsupported by Microsoft.
Again... enjoy! :-)
UPDATE in Late 2020, Benchmark vs the pywin32 library:
import time
import win32ui
from typing import Optional
from ctypes import wintypes, windll, create_unicode_buffer
def getForegroundWindowTitle() -> Optional[str]:
hWnd = windll.user32.GetForegroundWindow()
length = windll.user32.GetWindowTextLengthW(hWnd)
buf = create_unicode_buffer(length + 1)
windll.user32.GetWindowTextW(hWnd, buf, length + 1)
return buf.value if buf.value else None
def getForegroundWindowTitle_Win32UI() -> Optional[str]:
# WARNING: This code sometimes throws an exception saying
# "win32ui.error: No window is is in the foreground."
# which is total nonsense. My function doesn't fail that way.
return win32ui.GetForegroundWindow().GetWindowText()
iterations = 1_000_000
start_time = time.time()
for x in range(iterations):
foo = getForegroundWindowTitle()
elapsed1 = time.time() - start_time
print("Elapsed 1:", elapsed1, "seconds")
start_time = time.time()
for x in range(iterations):
foo = getForegroundWindowTitle_Win32UI()
elapsed2 = time.time() - start_time
print("Elapsed 2:", elapsed2, "seconds")
win32ui_pct_slower = ((elapsed2 / elapsed1) - 1) * 100
print("Win32UI library is", win32ui_pct_slower, "percent slower.")
Typical result after doing multiple runs on an AMD Ryzen 3900x:
My function: 4.5769994258880615 seconds
Win32UI library: 4.8619983196258545 seconds
Win32UI library is 6.226762715455125 percent slower.
However, the difference is small, so you may want to use the library now that it has come back to life (it had previously been dead since 2017). But you're going to have to deal with that library's weird "no window is in the foreground" exception, which my code doesn't suffer from (see the code comments in the benchmark code).
Either way... enjoy!

The following script should work on Linux, Windows and Mac. It is currently only tested on Linux (Ubuntu Mate Ubuntu 15.10).
Prerequisites
For Linux:
Install wnck (sudo apt-get install python-wnck on Ubuntu, see libwnck.)
For Windows:
Make sure win32gui is available
For Mac:
Make sure AppKit is available
The script
#!/usr/bin/env python
"""Find the currently active window."""
import logging
import sys
logging.basicConfig(format='%(asctime)s %(levelname)s %(message)s',
level=logging.DEBUG,
stream=sys.stdout)
def get_active_window():
"""
Get the currently active window.
Returns
-------
string :
Name of the currently active window.
"""
import sys
active_window_name = None
if sys.platform in ['linux', 'linux2']:
# Alternatives: https://unix.stackexchange.com/q/38867/4784
try:
import wnck
except ImportError:
logging.info("wnck not installed")
wnck = None
if wnck is not None:
screen = wnck.screen_get_default()
screen.force_update()
window = screen.get_active_window()
if window is not None:
pid = window.get_pid()
with open("/proc/{pid}/cmdline".format(pid=pid)) as f:
active_window_name = f.read()
else:
try:
from gi.repository import Gtk, Wnck
gi = "Installed"
except ImportError:
logging.info("gi.repository not installed")
gi = None
if gi is not None:
Gtk.init([]) # necessary if not using a Gtk.main() loop
screen = Wnck.Screen.get_default()
screen.force_update() # recommended per Wnck documentation
active_window = screen.get_active_window()
pid = active_window.get_pid()
with open("/proc/{pid}/cmdline".format(pid=pid)) as f:
active_window_name = f.read()
elif sys.platform in ['Windows', 'win32', 'cygwin']:
# https://stackoverflow.com/a/608814/562769
import win32gui
window = win32gui.GetForegroundWindow()
active_window_name = win32gui.GetWindowText(window)
elif sys.platform in ['Mac', 'darwin', 'os2', 'os2emx']:
# https://stackoverflow.com/a/373310/562769
from AppKit import NSWorkspace
active_window_name = (NSWorkspace.sharedWorkspace()
.activeApplication()['NSApplicationName'])
else:
print("sys.platform={platform} is unknown. Please report."
.format(platform=sys.platform))
print(sys.version)
return active_window_name
print("Active window: %s" % str(get_active_window()))

For Linux users:
All the answers provided required additional modules like "wx" that had numerous errors installing ("pip" failed on build), but I was able to modify this solution quite easily -> original source. There were bugs in the original (Python TypeError on regex)
import sys
import os
import subprocess
import re
def get_active_window_title():
root = subprocess.Popen(['xprop', '-root', '_NET_ACTIVE_WINDOW'], stdout=subprocess.PIPE)
stdout, stderr = root.communicate()
m = re.search(b'^_NET_ACTIVE_WINDOW.* ([\w]+)$', stdout)
if m != None:
window_id = m.group(1)
window = subprocess.Popen(['xprop', '-id', window_id, 'WM_NAME'], stdout=subprocess.PIPE)
stdout, stderr = window.communicate()
else:
return None
match = re.match(b"WM_NAME\(\w+\) = (?P<name>.+)$", stdout)
if match != None:
return match.group("name").strip(b'"')
return None
if __name__ == "__main__":
print(get_active_window_title())
The advantage is it works without additional modules. If you want it to work across multiple platforms, it's just a matter of changing the command and regex strings to get the data you want based on the platform (with the standard if/else platform detection shown above sys.platform).
On a side note: import wnck only works with python2.x when installed with "sudo apt-get install python-wnck", since I was using python3.x the only option was pypie which I have not tested. Hope this helps someone else.

There's really no need to import any external dependency for tasks like this. Python comes with a pretty neat foreign function interface - ctypes, which allows for calling C shared libraries natively. It even includes specific bindings for the most common Win32 DLLs.
E.g. to get the PID of the foregorund window:
import ctypes
from ctypes import wintypes
user32 = ctypes.windll.user32
h_wnd = user32.GetForegroundWindow()
pid = wintypes.DWORD()
user32.GetWindowThreadProcessId(h_wnd, ctypes.byref(pid))
print(pid.value)

In Linux under X11:
xdo_window_id = os.popen('xdotool getactivewindow').read()
print('xdo_window_id:', xdo_window_id)
will print the active window ID in decimal format:
xdo_window_id: 67113707
Note xdotool must be installed first:
sudo apt install xdotool
Note wmctrl uses hexadecimal format for window ID.

This only works on windows
import win32gui
import win32process
def get_active_executable_name():
try:
process_id = win32process.GetWindowThreadProcessId(
win32gui.GetForegroundWindow()
)
return ".".join(psutil.Process(process_id[-1]).name().split(".")[:-1])
except Exception as exception:
return None
I'll recommend checking out this answer for making it work on linux, mac and windows.

I'd been facing same problem with linux interface (Lubuntu 20).
What I do is using wmctrl and execute it with shell command from python.
First, Install wmctrl
sudo apt install wmctrl
Then, Add this code :
import os
os.system('wmctrl -a "Mozilla Firefox"')
ref wmctrl :
https://askubuntu.com/questions/21262/shell-command-to-bring-a-program-window-in-front-of-another

In Linux:
If you already have installed xdotool, you can just use:
from subprocess import run
def get__focused_window():
return run(['xdotool', 'getwindowfocus', 'getwindowpid', 'getwindowname'], capture_output=True).stdout.decode('utf-8').split()
While I was writing this answer I've realised that there were also:
A reference about "xdotool" on comments
& another slightly similar "xdotool" answer
So, I've decided to mention them here, too.

Just wanted to add in case it helps, I have a function for my program (It's a software for my PC's lighting I have this simple few line function:
def isRunning(process_name):
foregroundWindow = GetWindowText(GetForegroundWindow())
return process_name in foregroundWindow

Try using wxPython:
import wx
wx.GetActiveWindow()

Qt Clipboard operation does not work in tests on OSX

I have a widget where the mac shortcut Command+C works well interactively, and the content is correctly stored in the clipboard.
I am trying to implement the same behavior in the unittests. It works on other platforms, but not on Mac.
expected_clipboard = "whatever"
self._widget.show()
Test.processEvents()
QtTest.QTest.keyClick(self._widget, QtCore.Qt.Key_C, QtCore.Qt.ControlModifier)
Test.processEvents()
current_clipboard= QtGui.qApp.clipboard().text()
self.assertEqual(current_clipboard, expected_clipboard) # Fails.
According to the Qt documentation, ControlModifier is the proper corresponding entity for Command on Mac. I also tried MetaModifier just out of curiosity, but it doesn't work.
The action is correctly attached with the following code
self._action = QtGui.QAction('text', self)
action.connect(self._action, QtCore.SIGNAL('triggered()'), self.copyAction)
self._action.setShortcut(QtGui.QKeySequence.Copy)
self.addAction(self._action)
Qt 4.8 latest, osx 10.8.

Ok, the problem is that the window must be visible, raised and activated, otherwise OSX does not deliver events. Just call widget.raise_() and widget.activateWindow()

system wide shortcut for Mac OS X

So I was asked to port some internal helper applications to Mac OS X 10.7.
Works all quite welll as the platform dependent code is minimal anyhow, but one application needs a system wide shortcut to function (i.e. RegisterHotkey functionality) and I can't find any documentation on how I'd do this on a Mac.
The program is using a PyQt gui with Python 3.2. and the corresponding code for windows is basically:
def register_hotkey(self):
hwnd = int(self.winId())
modifiers, key = self._get_hotkey()
user32.RegisterHotKey(hwnd, self._MESSAGE_ID, modifiers, key)
and then to receive the hotkey events:
def winEvent(self, msg):
if msg.message == w32.WM_HOTKEY:
self.handle_hotkey()
return True, id(msg)
return False, id(msg)
Note that I don't need a python variant, I can easily write a simple c extension - so C/objective-c solutions are welcome as well.

I recently coded up an extension to quodlibet capturing multimedia keys (since absorbed into quodlibet itself); for your setup the same process applies.
I used the Quartz CGEventTapCreate hook and event loop, and the Cocoa AppKit framework to decipher key codes to achieve this.
The following code registers a python callback which is passed global key presses, and starts the event loop:
import Quartz
from AppKit import NSKeyUp, NSSystemDefined, NSEvent
# Set up a tap, with type of tap, location, options and event mask
tap = Quartz.CGEventTapCreate(
Quartz.kCGSessionEventTap, # Session level is enough for our needs
Quartz.kCGHeadInsertEventTap, # Insert wherever, we do not filter
Quartz.kCGEventTapOptionListenOnly, # Listening is enough
Quartz.CGEventMaskBit(NSSystemDefined), # NSSystemDefined for media keys
keyboardTapCallback,
None
)
runLoopSource = Quartz.CFMachPortCreateRunLoopSource(None, tap, 0)
Quartz.CFRunLoopAddSource(
Quartz.CFRunLoopGetCurrent(),
runLoopSource,
Quartz.kCFRunLoopDefaultMode
)
# Enable the tap
Quartz.CGEventTapEnable(tap, True)
# and run! This won't return until we exit or are terminated.
Quartz.CFRunLoopRun()
I defined a tap for system defined keys only (media keys); you'll have to specify a different event mask (CGEventMaskBit with one or more Event Types); e.g. Quartz.CGEventMaskBit(Quartz.kCGEventKeyUp) for key up events.
The callback should have the following signature (it implements the CGEventTapCallBack method from the Quartz API:
def keyboardTapCallback(proxy, type_, event, refcon):
# Convert the Quartz CGEvent into something more useful
keyEvent = NSEvent.eventWithCGEvent_(event)
I converted the Quartz event into a NSEvent, because all the information I could find on Mac multimedia keys was referring to that class.
In principle you can achieve the same thing with the AppKit APIs too, but then your Python application is treated as a Mac Application (visible in the Dock with an icon and everything), while I wanted this to be kept in the background altogether.

Using the power of google, I found this snippet of code, which allows the registration of global hotkeys for Mac OS X
You'll need to add the Carbon framework, and probably a bridged cast for ARC when passing the Objective-C self pointer to the C function.
At a minimum, you'll also need to:
#import <Carbon/Carbon.h>
The keycodes can be seen on this page explaining the virtual key codes.

Why has nobody ever mentioned the hammerspoon, which supports custom global system shortcuts, which can invoke shell command or launch UI application like Safari, PHOTOSHOP.
The following is an example written by me demonstrating how to invoke shell function with global hotkeys.
https://gist.github.com/BigSully/0e59ab97f148bc167ea19dbd42ebef4b
Use hs.execute to execute shell command, either non-interactive or interactive.
hs.hotkey.bind({"cmd", "alt", "ctrl"}, "P", function()
local output = hs.execute("toggleProxy", true)
hs.alert.show(output)
end)
or
Use hs.application.launchOrFocus to launch application
hs.application.launchOrFocus("Safari")

Programmatically detect system-proxy settings on Windows XP with Python

I develop a critical application used by a multi-national company. Users in offices all around the globe need to be able to install this application.
The application is actually a plugin to Excel and we have an automatic installer based on Setuptools' easy_install that ensures that all a project's dependancies are automatically installed or updated any time a user switches on their Excel. It all works very elegantly as users are seldom aware of all the installation which occurs entirely in the background.
Unfortunately we are expanding and opening new offices which all have different proxy settings. These settings seem to change from day to day so we cannot keep up with the outsourced security guys who change stuff without telling us. It sucks but we just have to work around it.
I want to programatically detect the system-wide proxy settings on the Windows workstations our users run:
Everybody in the organisazation runs Windows XP and Internet Explorer. I've verified that everybody can download our stuff from IE without problems regardless of where they are int the world.
So all I need to do is detect what proxy settings IE is using and make Setuptools use those settings. Theoretically all of this information should be in the Registry.. but is there a better way to find it that is guaranteed not to change with people upgrade IE? For example is there a Windows API call I can use to discover the proxy settings?
In summary:
We use Python 2.4.4 on Windows XP
We need to detect the Internet Explorer proxy settings (e.g. host, port and Proxy type)
I'm going to use this information to dynamically re-configure easy_install so that it can download the egg files via the proxy.
UPDATE0:
I forgot one important detail: Each site has an auto-config "pac" file.
There's a key in Windows\CurrentVersion\InternetSettings\AutoConfigURL which points to a HTTP document on a local server which contains what looks like a javascript file.
The pac script is basically a series of nested if-statements which compare URLs against a regexp and then eventually return the hostname of the chosen proxy-server. The script is a single javascript function called FindProxyForURL(url, host)
The challenge is therefore to find out for any given server which proxy to use. The only 100% guaranteed way to do this is to look up the pac file and call the Javascript function from Python.
Any suggestions? Is there a more elegant way to do this?

Here's a sample that should create a bullet green (proxy enable) or red (proxy disable) in your systray
It shows how to read and write in windows registry
it uses gtk
#!/usr/bin/env python
import gobject
import gtk
from _winreg import *
class ProxyNotifier:
def __init__(self):
self.trayIcon = gtk.StatusIcon()
self.updateIcon()
#set callback on right click to on_right_click
self.trayIcon.connect('popup-menu', self.on_right_click)
gobject.timeout_add(1000, self.checkStatus)
def isProxyEnabled(self):
aReg = ConnectRegistry(None,HKEY_CURRENT_USER)
aKey = OpenKey(aReg, r"Software\Microsoft\Windows\CurrentVersion\Internet Settings")
subCount, valueCount, lastModified = QueryInfoKey(aKey)
for i in range(valueCount):
try:
n,v,t = EnumValue(aKey,i)
if n == 'ProxyEnable':
return v and True or False
except EnvironmentError:
break
CloseKey(aKey)
def invertProxyEnableState(self):
aReg = ConnectRegistry(None,HKEY_CURRENT_USER)
aKey = OpenKey(aReg, r"Software\Microsoft\Windows\CurrentVersion\Internet Settings", 0, KEY_WRITE)
if self.isProxyEnabled() :
val = 0
else:
val = 1
try:
SetValueEx(aKey,"ProxyEnable",0, REG_DWORD, val)
except EnvironmentError:
print "Encountered problems writing into the Registry..."
CloseKey(aKey)
def updateIcon(self):
if self.isProxyEnabled():
icon=gtk.STOCK_YES
else:
icon=gtk.STOCK_NO
self.trayIcon.set_from_stock(icon)
def checkStatus(self):
self.updateIcon()
return True
def on_right_click(self, data, event_button, event_time):
self.invertProxyEnableState()
self.updateIcon()
if __name__ == '__main__':
proxyNotifier = ProxyNotifier()
gtk.main()

As far as I know, In a Windows environment, if no proxy environment variables are set, proxy settings are obtained from the registry's Internet Settings section. .
Isn't it enough?
Or u can get something useful info from registry:
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\ProxyServer
Edit:
sorry for don't know how to format comment's source code, I repost it here.
>>> import win32com.client
>>> js = win32com.client.Dispatch('MSScriptControl.ScriptControl')
>>> js.Language = 'JavaScript'
>>> js.AddCode('function add(a, b) {return a+b;}')
>>> js.Run('add', 1, 2)
3

Detect 64bit OS (windows) in Python

Does anyone know how I would go about detected what bit version Windows is under Python. I need to know this as a way of using the right folder for Program Files.
Many thanks

I think the best solution to the problem has been posted by Mark Ribau.
The best answer to the question for Python 2.7 and newer is:
def is_os_64bit():
return platform.machine().endswith('64')
On windows the cross-platform-function platform.machine() internally uses the environmental variables used in Matthew Scoutens answer.
I found the following values:
WinXP-32: x86
Vista-32: x86
Win7-64: AMD64
Debian-32: i686
Debian-64: x86_64
For Python 2.6 and older:
def is_windows_64bit():
if 'PROCESSOR_ARCHITEW6432' in os.environ:
return True
return os.environ['PROCESSOR_ARCHITECTURE'].endswith('64')
To find the Python interpreter bit version I use:
def is_python_64bit():
return (struct.calcsize("P") == 8)

I guess you should look in os.environ['PROGRAMFILES'] for the program files folder.

platform module -- Access to underlying platform’s identifying data
>>> import platform
>>> platform.architecture()
('32bit', 'WindowsPE')
On 64-bit Windows, 32-bit Python returns:
('32bit', 'WindowsPE')
And that means that this answer, even though it has been accepted, is incorrect. Please see some of the answers below for options that may work for different situations.

Came here searching for properly detecting if running on 64bit windows, compiling all the above into something more concise.
Below you will find a function to test if running on 64bit windows, a function to get the 32bit Program Files folder, and a function to get the 64bit Program Files folder; all regardless of running 32bit or 64bit python. When running 32bit python, most things report as if 32bit when running on 64bit, even os.environ['PROGRAMFILES'].
import os
def Is64Windows():
return 'PROGRAMFILES(X86)' in os.environ
def GetProgramFiles32():
if Is64Windows():
return os.environ['PROGRAMFILES(X86)']
else:
return os.environ['PROGRAMFILES']
def GetProgramFiles64():
if Is64Windows():
return os.environ['PROGRAMW6432']
else:
return None
Note: Yes, this is a bit hackish. All other methods that "should just work", do not work when running 32bit Python on 64bit Windows (at least for the various 2.x and 3.x versions I have tried).
Edits:
2011-09-07 - Added a note about why only this hackish method works properly.

def os_platform():
true_platform = os.environ['PROCESSOR_ARCHITECTURE']
try:
true_platform = os.environ["PROCESSOR_ARCHITEW6432"]
except KeyError:
pass
#true_platform not assigned to if this does not exist
return true_platform
http://blogs.msdn.com/b/david.wang/archive/2006/03/26/howto-detect-process-bitness.aspx

Many of these proposed solutions, such as platform.architecture(), fail because their results depend on whether you are running 32-bit or 64-bit Python.
The only reliable method I have found is to check for the existence of os.environ['PROGRAMFILES(X86)'], which is unfortunately hackish.

You should be using environment variables to access this. The program files directory is stored in the environment variable PROGRAMFILES on x86 Windows, the 32-bit program files is directory is stored in the PROGRAMFILES(X86) environment variable, these can be accessed by using os.environ('PROGRAMFILES').
Use sys.getwindowsversion() or the existence of PROGRAMFILES(X86) (if 'PROGRAMFILES(X86)' in os.environ) to determine what version of Windows you are using.

Following this documentation, try this code:
is_64bits = sys.maxsize > 2**32

Im aware that in comments of the question this method was already used.
This is the method the .net framework uses:
import ctypes
def is64_bit_os():
""" Returns wethever system is a 64bit operating system"""
is64bit = ctypes.c_bool()
handle = ctypes.windll.kernel32.GetCurrentProcess() # should be -1, because the current process is currently defined as (HANDLE) -1
success = ctypes.windll.kernel32.IsWow64Process(handle, ctypes.byref(is64bit)) #should return 1
return (success and is64bit).value
print(is64_bit_os())

I just found another way to do this, which may be useful in some situations.
import subprocess
import os
def os_arch():
os_arch = '32-bit'
if os.name == 'nt':
output = subprocess.check_output(['wmic', 'os', 'get', 'OSArchitecture'])
os_arch = output.split()[1]
else:
output = subprocess.check_output(['uname', '-m'])
if 'x86_64' in output:
os_arch = '64-bit'
else:
os_arch = '32-bit'
return os_arch
print 'os_arch=%s' % os_arch()
I tested this code in the following environments:
Ubuntu 16.04 + Python 2.7.12
Mac OS Sierra + Python 2.7.11
Windows 7 Pro 32-bit + Python 2.7.5 (32-bit)
Windows 10 Home 64-bit + Python 2.7.13 (32-bit)

The subject lines asks about detecting 64 or 32bit OS, while the body talks about determining the location of ProgramFiles. The latter has a couple of workable answers here. I'd like to add another solution generalized to handle StartMenu, Desktop, etc. as well as ProgramFiles: How to get path of Start Menu's Programs directory?

When you need to find out things about windows system, it is usually somewhere in the registry, according to MS documentation, you should look at (http://support.microsoft.com/kb/556009) this key value:
HKLM\HARDWARE\DESCRIPTION\System\CentralProcessor\0
and if it is:
0x00000020 (32 in decimal)
It is a 32 bit machine.

64-bit versions of Windows use something called registry redirection and reflection keys. There is a compatibility layer called WoW64 which enables compatibility of 32-bit applications. Starting from Windows 7 and Windows Server 2008 R2 WoW64 registry keys are not longer reflected but shared. You can read about it here:
registry-reflection: msdn.microsoft.com/en-us/library/aa384235(v=vs.85).aspx
affected-keys: msdn.microsoft.com/en-us/library/aa384253(v=vs.85).aspx
wikipedia: en.wikipedia.org/wiki/WoW64
All you need to do is detect existence of those keys. You can use _winreg for that. Use try: and try opening key, example:
try:
aReg = _winreg.OpenKey(_winreg.HKEY_LOCAL_MACHINE,"SOFTWARE\\Wow6432Node\\Microsoft\\Windows\\CurrentVersion\\Run")

import _winreg
def get_registry_value(key, subkey, value):
key = getattr(_winreg, key)
handle = _winreg.OpenKey(key, subkey )
(value, type) = _winreg.QueryValueEx(handle, value)
return value
windowsbit=cputype = get_registry_value(
"HKEY_LOCAL_MACHINE",
"SYSTEM\\CurrentControlSet\Control\\Session Manager\\Environment",
"PROCESSOR_ARCHITECTURE")
print windowsbit
just run this code
if you are working on 64 bit windows machine this will print AMD64
or if you are working on 32 bit it will print AMD32
i hope this code can help to solve this problem fully

This works for me in the Python versions I use: 2.7 and 2.5.4
import win32com.client
import _winreg
shell = win32com.client.Dispatch('WScript.Shell')
proc_arch = shell.ExpandEnvironmentStrings(r'%PROCESSOR_ARCHITECTURE%').lower()
if proc_arch == 'x86':
print "32 bit"
elif proc_arch == 'amd64':
print "64 bit"
else:
raise Exception("Unhandled arch: %s" % proc_arch)

Just to update this old thread - it looks like the platform module reports the correct architecture now (at least, in Python 2.7.8):
c:\python27\python.exe -c "import platform; print platform.architecture(), platform.python_version()"
('32bit', 'WindowsPE') 2.7.6
c:\home\python278-x64\python.exe -c "import platform; print platform.architecture(), platform.python_version()"
('64bit', 'WindowsPE') 2.7.8
(sorry I don't have the rep to comment on the first answer which still claims to be wrong :)

import platform
platform.architecture()[0]
It will return '32bit' or '64bit' depending on system architecture.

The solution posted by Alexander Brüsch is the correct solution, but it has a bug that only reveals itself on python3.x. He neglected to cast the returned value from GetCurrentProcess() to a HANDLE type. Passing a simple integer as the first parameter of IsWow64Process() returns 0 (which is an error flag from win32api). Also, Alexander incorrectly handles the return statement (success has no .value attribute).
For those who stumble on this thread, here is the corrected code:
import ctypes
def is64_bit_os():
"""Returns True if running 32-bit code on 64-bit operating system"""
is64bit = ctypes.c_bool()
handle = ctypes.wintypes.HANDLE(ctypes.windll.kernel32.GetCurrentProcess())
success = ctypes.windll.kernel32.IsWow64Process(handle, ctypes.byref(is64bit))
return success and is64bit.value
print(is64_bit_os())

There is a function named machine in platform module. I installed both Python3.8 32-bit and 64-bit versions on the same 64-bit machine with 64-bit Windows 10 and here is what I found:
And it looks like platform.machine returns machine architecture without bothering what type of python is installed. so here is my
final compilation
import platform
def is_64bit():
return platform.machine().endswith('64')

Most of the answers here are incorrect :/
Here is a simple translation of the well known method used in CMD and this is how microsoft do it too.
import os
_os_bit=64
if os.environ.get('PROCESSOR_ARCHITECTURE').lower() == 'x86' and os.environ.get('PROCESSOR_ARCHITEW6432') is None: _os_bit=32
print(_os_bit)
but remember: Windows 10 on ARM includes an x86-on-ARM64 emulation, so the possible values for PROCESSOR_ARCHITECTURE are: AMD64 or IA64 or ARM64 or x86

A solution, putting together the options from the links below and using os module:
import os
#next save the response from the command prompt saved to a file
window = os.system('PowerShell.exe "gwmi win32_operatingsystem | select osarchitecture" > prompt.txt')
#next read the file
f = open('prompt.txt','r')
windowsos = f.readlines()
f.close()
print(windowsos[3][:-1])
https://datatofish.com/command-prompt-python/
https://www.radishlogic.com/windows/how-to-check-if-your-windows-10-is-64-bit-or-32-bit/
https://www.tutorialspoint.com/how-to-run-a-powershell-script-from-the-command-prompt

import struct
def is64Windows():
return struct.calcsize('P') * 8 == 64

There should be a directory under Windows 64bit, a Folder called \Windows\WinSxS64 for 64 bit, under Windows 32bit, it's WinSxS.