Can Python be used to send a true key down event to Mac

Question

My question is, is there any way to reliably hold a key down on a mac with applescript/python?

I have search almost everywhere for topics like this, however, none of them cut it. I am attempting to use Python to read serial information from an Arduino, then relay those signals as keypresses. I have seen how to use applescript to send a "key down" to the system event, as shown in the following code:

(Python code)
    def SendDown(key):
    string = str(key)
    cmd = """osascript -e 'tell application "System Events" to key down (key code """ + string   + ")'"
    os.system(cmd)

This code works generally, however, I want to control the Google flight simulator. When I attempt to do this, the key presses seem to be way to quick and the flight simulator or the basic google earth map moves fractions of what I would expect.

They way I am using this code is essentially as follows (suedocode)

if (ArduinoMessage == "left"):
    SendDown(leftKey) #leftKey has been set to 123 -- the code for the left arrow key
    etc...

From my point of view, the key down event I'm sending is essentially a quick keystroke and the key is not being held down. I tried programming the key event directly in applescript and had a little bit of success. My code looked something like this:

tell application "System Events"
    repeat 50 times    
        key down (key code 123)
    end repeat
    key up (key code 123)
end tell

That code moved the google earth map more than I have been getting, but it took a long time to get it to move a small amount (far less than the normal arrow keys). Then I tried to write that applescript into Python and lost all improvement.

So I restate the question -- is there any way to reliably hold a key down on a mac with applescript/python?

I was able to get this to work on Windows fairly easily, however, I was able to use a Windows only library called SendKeys that is designed for applications such as this.

Any help would be appreciated.

Thanks,

Jake

Answer 1

Use PyUserInput. Try following code.

import time

import pykeyboard


# TODO: Replace following two lines with the code that activate the application.
print('Activate the application 3 seconds.')
time.sleep(3)

k = pykeyboard.PyKeyboard()
k.press_key(k.left_key)
time.sleep(1) # Hold down left key for 1 second.
k.release_key(k.left_key)

Unfortunately I don't have Mac. I tested in Linux, Windows.