How can I send keystrokes and mouse movement to a specific PID?

Question

How can I send keystrokes and mouse movements to a specific running program through its PID. I've used both pywinauto and pynput, and they work great, but I want to send keys to a program that is not in focus. I found this question: How to I send keystroke to Linux process in Python by PID? but it never explains what filePath is a path to.

If you could help solve for this example, that would be great! I want to send the "d" key to an open Minecraft tab for 10 seconds, and then send the "a" key for the next 10 seconds and stop. I would need this to be able to run in the background, so it could not send the keys to the computer as a whole, but only to the Minecraft tab. I am on Windows 10 by the way.

Any help would be appreciated!

Answer 1

With ahk you can do this with Python+AutoHotkey

pip install ahk
pip install "ahk[binary]"

from ahk import AHK
from ahk.window import Window
ahk = AHK()
win = Window.from_pid(ahk, pid='20366')
win.send('abc') # send keys directly to the window

Note that some programs may simply ignore inputs when they are not in focus. However, you can test this works in general even when not in focus by testing with a program like notepad

Full disclosure: I author the ahk library.

Answer 2

Pretty sure you won't be able to, at least not easily let me explain a little bit how all of this works.

Lets start with the hardware and os, the OS has certain functions to read the input you give the computer. This input goes into a "pipe", the OS is reading input, and putting into the pipe, on the other side of the pipe there may be an application running, or it may not. The OS typically manages this (which app to put on the pipe listening) by defining which app/window is active. Apps access this pipe with the API given by the OS, they read the input and decide on it.

The libraries you cited above, change the values of the keyboard and mouse, in other words, they make the OS read other values, not the real ones, then the OS puts them in the "pipe", and are read by the app that is listening on the pipe (the one active). Some apps have their own API's for this, but I would guess Minecraft doesn't. If they don't have an API, what can you do? well, as I said, nothing easy, first of all "hacking" the app, in other words change it to listen to some other input/output rather than the one given by the OS, (this would be you making your own API). The other one would be you changing the OS, which would also be extremely hard, but maybe a tiny bitty easier. It also depends on your OS, I think Microsoft does offer input injection api's

So, simple options, first, run a VM with a GUI and use pywinauto, pyautogui, etc. The other option would be if you can run it in the browser, do so, and use something like Selenium to automate the input.

Quick note, why does selenium works and the browser can read input in the background? Easy, it's not, it just executes the code it would execute if it would have read the input! javascript, cool isn't