With python 3, I'd like to get a handle to another window (not part of my application) such that I can either:
In case it is important, I am using Windows XP (edit: works in Windows 7 also).
I found this solution, but it is not quite what I need since it is full screen and more importantly, PIL to the best of my knowledge does not support 3.x yet.
This will take a new opened window and make a screenshot of it and then crop it with PIL also possible to find your specific window with pygetwindow.getAllTitles() and then fill in your window name in z3 to get screenshot of only that window.
If you definitely not want to use PIL you can maximize window with pygetwindow module and then make a screenshot with pyautogui module.
Note: not tested on Windows XP (but tested on Windows 10)
import pygetwindow
import time
import os
import pyautogui
import PIL
# get screensize
x,y = pyautogui.size()
print(f"width={x}\theight={y}")
x2,y2 = pyautogui.size()
x2,y2=int(str(x2)),int(str(y2))
print(x2//2)
print(y2//2)
# find new window title
z1 = pygetwindow.getAllTitles()
time.sleep(1)
print(len(z1))
# test with pictures folder
os.startfile("C:\\Users\\yourname\\Pictures")
time.sleep(1)
z2 = pygetwindow.getAllTitles()
print(len(z2))
time.sleep(1)
z3 = [x for x in z2 if x not in z1]
z3 = ''.join(z3)
time.sleep(3)
# also able to edit z3 to specified window-title string like: "Sublime Text (UNREGISTERED)"
my = pygetwindow.getWindowsWithTitle(z3)[0]
# quarter of screen screensize
x3 = x2 // 2
y3 = y2 // 2
my.resizeTo(x3,y3)
# top-left
my.moveTo(0, 0)
time.sleep(3)
my.activate()
time.sleep(1)
# save screenshot
p = pyautogui.screenshot()
p.save(r'C:\\Users\\yourname\\Pictures\\\\p.png')
# edit screenshot
im = PIL.Image.open('C:\\Users\\yourname\\Pictures\\p.png')
im_crop = im.crop((0, 0, x3, y3))
im_crop.save('C:\\Users\\yourname\\Pictures\\p.jpg', quality=100)
# close window
time.sleep(1)
my.close()
The solution here gets a screenshot of a single Window (so can work if the Window is in the background).
Other solutions of this page take picture of the part of the screen the window is on, and thus need to bring the Window to the front first.