python – How to generate keyboard events?

python – How to generate keyboard events?

It can be done using ctypes:

import ctypes
from ctypes import wintypes
import time

user32 = ctypes.WinDLL(user32, use_last_error=True)

INPUT_MOUSE    = 0
INPUT_KEYBOARD = 1
INPUT_HARDWARE = 2

KEYEVENTF_EXTENDEDKEY = 0x0001
KEYEVENTF_KEYUP       = 0x0002
KEYEVENTF_UNICODE     = 0x0004
KEYEVENTF_SCANCODE    = 0x0008

MAPVK_VK_TO_VSC = 0

# msdn.microsoft.com/en-us/library/dd375731
VK_TAB  = 0x09
VK_MENU = 0x12

# C struct definitions

wintypes.ULONG_PTR = wintypes.WPARAM

class MOUSEINPUT(ctypes.Structure):
    _fields_ = ((dx,          wintypes.LONG),
                (dy,          wintypes.LONG),
                (mouseData,   wintypes.DWORD),
                (dwFlags,     wintypes.DWORD),
                (time,        wintypes.DWORD),
                (dwExtraInfo, wintypes.ULONG_PTR))

class KEYBDINPUT(ctypes.Structure):
    _fields_ = ((wVk,         wintypes.WORD),
                (wScan,       wintypes.WORD),
                (dwFlags,     wintypes.DWORD),
                (time,        wintypes.DWORD),
                (dwExtraInfo, wintypes.ULONG_PTR))

    def __init__(self, *args, **kwds):
        super(KEYBDINPUT, self).__init__(*args, **kwds)
        # some programs use the scan code even if KEYEVENTF_SCANCODE
        # isnt set in dwFflags, so attempt to map the correct code.
        if not self.dwFlags & KEYEVENTF_UNICODE:
            self.wScan = user32.MapVirtualKeyExW(self.wVk,
                                                 MAPVK_VK_TO_VSC, 0)

class HARDWAREINPUT(ctypes.Structure):
    _fields_ = ((uMsg,    wintypes.DWORD),
                (wParamL, wintypes.WORD),
                (wParamH, wintypes.WORD))

class INPUT(ctypes.Structure):
    class _INPUT(ctypes.Union):
        _fields_ = ((ki, KEYBDINPUT),
                    (mi, MOUSEINPUT),
                    (hi, HARDWAREINPUT))
    _anonymous_ = (_input,)
    _fields_ = ((type,   wintypes.DWORD),
                (_input, _INPUT))

LPINPUT = ctypes.POINTER(INPUT)

def _check_count(result, func, args):
    if result == 0:
        raise ctypes.WinError(ctypes.get_last_error())
    return args

user32.SendInput.errcheck = _check_count
user32.SendInput.argtypes = (wintypes.UINT, # nInputs
                             LPINPUT,       # pInputs
                             ctypes.c_int)  # cbSize

# Functions

def PressKey(hexKeyCode):
    x = INPUT(type=INPUT_KEYBOARD,
              ki=KEYBDINPUT(wVk=hexKeyCode))
    user32.SendInput(1, ctypes.byref(x), ctypes.sizeof(x))

def ReleaseKey(hexKeyCode):
    x = INPUT(type=INPUT_KEYBOARD,
              ki=KEYBDINPUT(wVk=hexKeyCode,
                            dwFlags=KEYEVENTF_KEYUP))
    user32.SendInput(1, ctypes.byref(x), ctypes.sizeof(x))

def AltTab():
    Press Alt+Tab and hold Alt key for 2 seconds
    in order to see the overlay.
    
    PressKey(VK_MENU)   # Alt
    PressKey(VK_TAB)    # Tab
    ReleaseKey(VK_TAB)  # Tab~
    time.sleep(2)
    ReleaseKey(VK_MENU) # Alt~

if __name__ == __main__:
    AltTab()

hexKeyCode is the virtual keyboard mapping as defined by the Windows API. The list of codes is available on MSDN: Virtual-Key Codes (Windows)

For both python3 and python2 you can use pyautogui (pip install pyautogui)

from pyautogui import press, typewrite, hotkey

press(a)
typewrite(quick brown fox)
hotkey(ctrl, w)

Its also crossplatform with Windows, OSX, and Ubuntu LTS.

python – How to generate keyboard events?

I tried lib keyboard and it works good on Windows, Mac and Linux. Below line helps me switch tabs in browser:

keyboard.press_and_release(ctrl+tab)