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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()

Get full computer name from a network drive letter in python

I am using python to populate a table with the file pathways of a number of stored files. However the pathway needs to have the full network drive computer name not just the drive letter, ie
//ComputerName/folder/subfolder/file
not
P:/folder/subfolder/file
I have investigated using the win32api, win32file, and os.path modules but nothing is looking like its able to do it. I need something like win32api.GetComputerName() but with the ability to drop in a known drive letter as an argument and it return the computer name that is mapped to the letter.
So is there anyway in python to look up a drive letter and get back the computer name?

Network drives are mapped using the Windows Networking API that's exported by mpr.dll (multiple provider router). You can create a network drive via WNetAddConnection2. To get the remote path that's associated with a local device, call WNetGetConnection. You can do this using ctypes as follows:
import ctypes
from ctypes import wintypes
mpr = ctypes.WinDLL('mpr')
ERROR_SUCCESS = 0x0000
ERROR_MORE_DATA = 0x00EA
wintypes.LPDWORD = ctypes.POINTER(wintypes.DWORD)
mpr.WNetGetConnectionW.restype = wintypes.DWORD
mpr.WNetGetConnectionW.argtypes = (wintypes.LPCWSTR,
wintypes.LPWSTR,
wintypes.LPDWORD)
def get_connection(local_name):
length = (wintypes.DWORD * 1)()
result = mpr.WNetGetConnectionW(local_name, None, length)
if result != ERROR_MORE_DATA:
raise ctypes.WinError(result)
remote_name = (wintypes.WCHAR * length[0])()
result = mpr.WNetGetConnectionW(local_name, remote_name, length)
if result != ERROR_SUCCESS:
raise ctypes.WinError(result)
return remote_name.value
For example:
>>> subprocess.call(r'net use Y: \\live.sysinternals.com\tools')
The command completed successfully.
0
>>> print(get_connection('Y:'))
\\live.sysinternals.com\tools

I think you just need to look at more of pywin32... As you can see here, there is already an API that converts local drive names to full UNC paths.
For completeness, here is some code that works for me.
import win32wnet
import sys
print(win32wnet.WNetGetUniversalName(sys.argv[1], 1))
And this gives me something like this when I run it:
C:\test>python get_unc.py i:\some\path
\\machine\test_share\some\path

you could run net use and parse the output.
i am posting this from my mobile but i am going to improve this answer when i am in front of a real computer.
here are some links, that can help in the meantime:
https://docs.python.org/2/library/subprocess.html#module-subprocess.
https://technet.microsoft.com/en-us/library/gg651155.aspx.

My answer to a similar question:
Here's how to do it in python ≥ 3.4, with no dependencies!*
from pathlib import Path
def unc_drive(file_path):
return str(Path(file_path).resolve())
*Note: I just found a situation in which this method fails. One of my company's network shares has permissions setup such that this method raises a PermissionError. In this case, win32wnet.WNetGetUniversalName is a suitable fallback.

If you just need the hostname, you can use the socket module:
socket.gethostname()
or you may want to use the os module:
os.uname()[1]
os.uname() returns a 5 tuple that contains (sysname, nodename, release, version, machine)

Alternative to psutil.Process(pid).name

I have measured the performance of psutil.Process(pid).name and it turns out that it is more than ten times slower than for example psutil.Process(pid).exe. Because the last one of these functions requires different privileges over the path, I cannot just just extract the filename from the path. My question is: Are there any alternatives to psutil.Process(pid).name, which does the same?

You mentioned this is for windows. I took a look at what psutil does for windows. It looks like psutil.Process().name is using the windows tool help API. If you look at psutil's Process code and trace .name, it goes to get_name() in process_info.c. It is looping through all the pids on your system until it finds the one you're looking for. I think this may be a limitation of the toolhelp API. But this is why it's slower than .exe, which uses a different API path, that (as you pointed out), requires additional privilege.
The solution I came up with is to use ctypes and ctypes.windll to call the windows ntapi directly. It only needs PROCESS_QUERY_INFORMATION, which is different than PROCESS_ALL_ACCESS:
import ctypes
import os.path
# duplicate the UNICODE_STRING structure from the windows API
class UNICODE_STRING(ctypes.Structure):
_fields_ = [
('Length', ctypes.c_short),
('MaximumLength', ctypes.c_short),
('Buffer', ctypes.c_wchar_p)
]
# args
pid = 8000 # put your pid here
# define some constants; from windows API reference
MAX_TOTAL_PATH_CHARS = 32767
PROCESS_QUERY_INFORMATION = 0x0400
PROCESS_IMAGE_FILE_NAME = 27
# open handles
ntdll = ctypes.windll.LoadLibrary('ntdll.dll')
process = ctypes.windll.kernel32.OpenProcess(PROCESS_QUERY_INFORMATION,
False, pid)
# allocate memory
buflen = (((MAX_TOTAL_PATH_CHARS + 1) * ctypes.sizeof(ctypes.c_wchar)) +
ctypes.sizeof(UNICODE_STRING))
buffer = ctypes.c_char_p(' ' * buflen)
# query process image filename and parse for process "name"
ntdll.NtQueryInformationProcess(process, PROCESS_IMAGE_FILE_NAME, buffer,
buflen, None)
pustr = ctypes.cast(buffer, ctypes.POINTER(UNICODE_STRING))
print os.path.split(pustr.contents.Buffer)[-1]
# cleanup
ctypes.windll.kernel32.CloseHandle(process)
ctypes.windll.kernel32.FreeLibrary(ntdll._handle)

As of psutil 1.1.0 this problem has been fixed, see https://code.google.com/p/psutil/issues/detail?id=426

Python mmap ctypes - read only

I think I have the opposite problem as described here. I have one process writing data to a log, and I want a second process to read it, but I don't want the 2nd process to be able to modify the contents. This is potentially a large file, and I need random access, so I'm using python's mmap module.
If I create the mmap as read/write (for the 2nd process), I have no problem creating ctypes object as a "view" of the mmap object using from_buffer. From a cursory look at the c-code, it looks like this is a cast, not a copy, which is what I want. However, this breaks if I make the mmap ACCESS_READ, throwing an exception that from_buffer requires write privileges.
I think I want to use ctypes from_address() method instead, which doesn't appear to need write access. I'm probably missing something simple, but I'm not sure how to get the address of the location within an mmap. I know I can use ACCESS_COPY (so write operations show up in memory, but aren't persisted to disk), but I'd rather keep things read only.
Any suggestions?

I ran into a similar issue (unable to setup a readonly mmap) but I was using only the python mmap module. Python mmap 'Permission denied' on Linux
I'm not sure it is of any help to you since you don't want the mmap to be private?

Ok, from looking at the mmap .c code, I don't believe it supports this use case. Also, I found that the performance pretty much sucks - for my use case. I'd be curious what kind performance others see, but I found that it took about 40 sec to walk through a binary file of 500 MB in Python. This is creating a mmap, then turning the location into a ctype object with from_buffer(), and using the ctypes object to decipher the size of the object so I could step to the next object. I tried doing the same thing directly in c++ from msvc. Obviously here I could cast directly into an object of the correct type, and it was fast - less than a second (this is with a core 2 quad and ssd).
I did find that I could get a pointer with the following
firstHeader = CEL_HEADER.from_buffer(map, 0) #CEL_HEADER is a ctypes Structure
pHeader = pointer(firstHeader)
#Now I can use pHeader[ind] to get a CEL_HEADER object
#at an arbitrary point in the file
This doesn't get around the original problem - the mmap isn't read-only, since I still need to use from_buffer for the first call. In this config, it still took around 40 sec to process the whole file, so it looks like the conversion from a pointer into ctypes structs is killing the performance. That's just a guess, but I don't see a lot of value in tracking it down further.
I'm not sure my plan will help anyone else, but I'm going to try to create a c module specific to my needs based on the mmap code. I think I can use the fast c-code handling to index the binary file, then expose only small parts of the file at a time through calls into ctypes/python objects. Wish me luck.
Also, as a side note, Python 2.7.2 was released today (6/12/11), and one of the changes is an update to the mmap code so that you can use a python long to set the file offset. This lets you use mmap for files over 4GB on 32-bit systems. See Issue #4681 here

Ran into this same problem, we needed the from_buffer interface and wanted read only access. From the python docs https://docs.python.org/3/library/mmap.html "Assignment to an ACCESS_COPY memory map affects memory but does not update the underlying file."
If it's acceptable for you to use an anonymous file backing you can use ACCESS_COPY
An example: open two cmd.exe or terminals and in one terminal:
mm_file_write = mmap.mmap(-1, 4096, access=mmap.ACCESS_WRITE, tagname="shmem")
mm_file_read = mmap.mmap(-1, 4096, access=mmap.ACCESS_COPY, tagname="shmem")
write = ctypes.c_int.from_buffer(mm_file_write)
read = ctypes.c_int.from_buffer(mm_file_read)
try:
while True:
value = int(input('enter an integer using mm_file_write: '))
write.value = value
print('updated value')
value = int(input('enter an integer using mm_file_read: '))
#read.value assignment doesnt update anonymous backed file
read.value = value
print('updated value')
except KeyboardInterrupt:
print('got exit event')
In the other terminal do:
mm_file = mmap.mmap(-1, 4096, access=mmap.ACCESS_WRITE, tagname="shmem")
i = None
try:
while True:
new_i = struct.unpack('i', mm_file[:4])
if i != new_i:
print('i: {} => {}'.format(i, new_i))
i = new_i
time.sleep(0.1)
except KeyboardInterrupt:
print('Stopped . . .')
And you will see that the second process does not receive updates when the first process writes using ACCESS_COPY

Available disk space on an SMB share, via Python

Does anyone know a way to get the amount of space available on a Windows (Samba) share via Python 2.6 with its standard library? (also running on Windows)
e.g.
>>> os.free_space("\\myshare\folder") # return free disk space, in bytes
1234567890

If PyWin32 is available:
free, total, totalfree = win32file.GetDiskFreeSpaceEx(r'\\server\share')
Where free is a amount of free space available to the current user, and totalfree is amount of free space total. Relevant documentation: PyWin32 docs, MSDN.
If PyWin32 is not guaranteed to be available, then for Python 2.5 and higher there is ctypes module in stdlib. Same function, using ctypes:
import sys
from ctypes import *
c_ulonglong_p = POINTER(c_ulonglong)
_GetDiskFreeSpace = windll.kernel32.GetDiskFreeSpaceExW
_GetDiskFreeSpace.argtypes = [c_wchar_p, c_ulonglong_p, c_ulonglong_p, c_ulonglong_p]
def GetDiskFreeSpace(path):
if not isinstance(path, unicode):
path = path.decode('mbcs') # this is windows only code
free, total, totalfree = c_ulonglong(0), c_ulonglong(0), c_ulonglong(0)
if not _GetDiskFreeSpace(path, pointer(free), pointer(total), pointer(totalfree)):
raise WindowsError
return free.value, total.value, totalfree.value
Could probably be done better but I'm not really familiar with ctypes.

The standard library has the os.statvfs() function, but unfortunately it's only available on Unix-like platforms.
In case there is some cygwin-python maybe it would work there?