Python script to simulate keypresses in Windows

"""Simulates keypresses

Based on:
https://stackoverflow.com/questions/14489013/simulate-python-keypresses-for-controlling-a-game

Key scan codes:
https://docs.microsoft.com/en-us/previous-versions/visualstudio/visual-studio-6.0/aa299374(v=vs.60)?redirectedfrom=MSDN

"""
import ctypes
import time
import random


# DirectInput keyboard scan codes
# https://gist.github.com/tracend/912308
class Key:
    ESCAPE = 0x01
    NUM1 = 0x02
    NUM2 = 0x03
    NUM3 = 0x04
    NUM4 = 0x05
    NUM5 = 0x06
    NUM6 = 0x07
    NUM7 = 0x08
    NUM8 = 0x09
    NUM9 = 0x0A
    NUM0 = 0x0B
    MINUS = 0x0C  # - on main keyboard
    EQUALS = 0x0D
    BACK = 0x0E  # backspace
    TAB = 0x0F
    Q = 0x10
    W = 0x11
    E = 0x12
    R = 0x13
    T = 0x14
    Y = 0x15
    U = 0x16
    I = 0x17
    O = 0x18
    P = 0x19
    LBRACKET = 0x1A
    RBRACKET = 0x1B
    RETURN = 0x1C  # Enter on main keyboard
    LCONTROL = 0x1D
    A = 0x1E
    S = 0x1F
    D = 0x20
    F = 0x21
    G = 0x22
    H = 0x23
    J = 0x24
    K = 0x25
    L = 0x26
    SEMICOLON = 0x27
    APOSTROPHE = 0x28
    GRAVE = 0x29  # accent grave
    LSHIFT = 0x2A
    BACKSLASH = 0x2B
    Z = 0x2C
    X = 0x2D
    C = 0x2E
    V = 0x2F
    B = 0x30
    N = 0x31
    M = 0x32
    COMMA = 0x33
    PERIOD = 0x34  # . on main keyboard
    SLASH = 0x35  # / on main keyboard
    RSHIFT = 0x36
    MULTIPLY = 0x37  # * on numeric keypad
    LMENU = 0x38  # left Alt
    SPACE = 0x39
    CAPITAL = 0x3A
    F1 = 0x3B
    F2 = 0x3C
    F3 = 0x3D
    F4 = 0x3E
    F5 = 0x3F
    F6 = 0x40
    F7 = 0x41
    F8 = 0x42
    F9 = 0x43
    F10 = 0x44
    NUMLOCK = 0x45
    SCROLL = 0x46  # Scroll Lock
    NUMPAD7 = 0x47
    NUMPAD8 = 0x48
    NUMPAD9 = 0x49
    SUBTRACT = 0x4A  # - on numeric keypad
    NUMPAD4 = 0x4B
    NUMPAD5 = 0x4C
    NUMPAD6 = 0x4D
    ADD = 0x4E  # + on numeric keypad
    NUMPAD1 = 0x4F
    NUMPAD2 = 0x50
    NUMPAD3 = 0x51
    NUMPAD0 = 0x52
    DECIMAL = 0x53  # . on numeric keypad
    OEM_102 = 0x56  # <> or \| on RT 102-key keyboard (Non-U.S.)
    F11 = 0x57
    F12 = 0x58
    F13 = 0x64  # (NEC PC98)
    F14 = 0x65  # (NEC PC98)
    F15 = 0x66  # (NEC PC98)
    KANA = 0x70  # (Japanese keyboard)
    ABNT_C1 = 0x73  # /? on Brazilian keyboard
    CONVERT = 0x79  # (Japanese keyboard)
    NOCONVERT = 0x7B  # (Japanese keyboard)
    YEN = 0x7D  # (Japanese keyboard)
    ABNT_C2 = 0x7E  # Numpad . on Brazilian keyboard
    NUMPADEQUALS = 0x8D  # = on numeric keypad (NEC PC98)
    PREVTRACK = 0x90  # Previous Track (DIK_CIRCUMFLEX on Japanese keyboard)
    AT = 0x91  # (NEC PC98)
    COLON = 0x92  # (NEC PC98)
    UNDERLINE = 0x93  # (NEC PC98)
    KANJI = 0x94  # (Japanese keyboard)
    STOP = 0x95  # (NEC PC98)
    AX = 0x96  # (Japan AX)
    UNLABELED = 0x97  # (J3100)
    NEXTTRACK = 0x99  # Next Track
    NUMPADENTER = 0x9C  # Enter on numeric keypad
    RCONTROL = 0x9D
    MUTE = 0xA0  # Mute
    CALCULATOR = 0xA1  # Calculator
    PLAYPAUSE = 0xA2  # Play / Pause
    MEDIASTOP = 0xA4  # Media Stop
    VOLUMEDOWN = 0xAE  # Volume -
    VOLUMEUP = 0xB0  # Volume +
    WEBHOME = 0xB2  # Web home
    NUMPADCOMMA = 0xB3  # , on numeric keypad (NEC PC98)
    DIVIDE = 0xB5  # / on numeric keypad
    SYSRQ = 0xB7
    RMENU = 0xB8  # right Alt
    PAUSE = 0xC5  # Pause
    HOME = 0xC7  # Home on arrow keypad
    UP = 0xC8  # UpArrow on arrow keypad
    PRIOR = 0xC9  # PgUp on arrow keypad
    LEFT = 0xCB  # LeftArrow on arrow keypad
    RIGHT = 0xCD  # RightArrow on arrow keypad
    END = 0xCF  # End on arrow keypad
    DOWN = 0xD0  # DownArrow on arrow keypad
    NEXT = 0xD1  # PgDn on arrow keypad
    INSERT = 0xD2  # Insert on arrow keypad
    DELETE = 0xD3  # Delete on arrow keypad
    LWIN = 0xDB  # Left Windows key
    RWIN = 0xDC  # Right Windows key
    APPS = 0xDD  # AppMenu key
    POWER = 0xDE  # System Power
    SLEEP = 0xDF  # System Sleep
    WAKE = 0xE3  # System Wake
    WEBSEARCH = 0xE5  # Web Search
    WEBFAVORITES = 0xE6  # Web Favorites
    WEBREFRESH = 0xE7  # Web Refresh
    WEBSTOP = 0xE8  # Web Stop
    WEBFORWARD = 0xE9  # Web Forward
    WEBBACK = 0xEA  # Web Back
    MYCOMPUTER = 0xEB  # My Computer
    MAIL = 0xEC  # Mail
    MEDIASELECT = 0xED  # Media Select


SendInput = ctypes.windll.user32.SendInput

UnsignedLongPointer = ctypes.POINTER(ctypes.c_ulong)


class KeyBdInput(ctypes.Structure):
    _fields_ = [("wVk", ctypes.c_ushort),
                ("wScan", ctypes.c_ushort),
                ("dwFlags", ctypes.c_ulong),
                ("time", ctypes.c_ulong),
                ("dwExtraInfo", UnsignedLongPointer)]


class HardwareInput(ctypes.Structure):
    _fields_ = [("uMsg", ctypes.c_ulong),
                ("wParamL", ctypes.c_short),
                ("wParamH", ctypes.c_ushort)]


class MouseInput(ctypes.Structure):
    _fields_ = [("dx", ctypes.c_long),
                ("dy", ctypes.c_long),
                ("mouseData", ctypes.c_ulong),
                ("dwFlags", ctypes.c_ulong),
                ("time", ctypes.c_ulong),
                ("dwExtraInfo", UnsignedLongPointer)]


class Input_I(ctypes.Union):
    _fields_ = [("ki", KeyBdInput),
                ("mi", MouseInput),
                ("hi", HardwareInput)]


class Input(ctypes.Structure):
    _fields_ = [("type", ctypes.c_ulong),
                ("ii", Input_I)]


def press_key(hexKeyCode):
    extra = ctypes.c_ulong(0)
    ii_ = Input_I()
    ii_.ki = KeyBdInput(0, hexKeyCode, 0x0008, 0, ctypes.pointer(extra))
    x = Input(ctypes.c_ulong(1), ii_)
    ctypes.windll.user32.SendInput(1, ctypes.pointer(x), ctypes.sizeof(x))


def release_key(hexKeyCode):
    extra = ctypes.c_ulong(0)
    ii_ = Input_I()
    ii_.ki = KeyBdInput(0, hexKeyCode, 0x0008 | 0x0002, 0, ctypes.pointer(extra))
    x = Input(ctypes.c_ulong(1), ii_)
    ctypes.windll.user32.SendInput(1, ctypes.pointer(x), ctypes.sizeof(x))


INITIAL_WAIT = 5
CRYO_PERIOD_MIN = 120
CRYO_PERIOD_MAX = 290


def use():
    press_key(Key.F)
    time.sleep(0.1)
    release_key(Key.F)


def main():
    print('Waiting for %d seconds to let you switch back to the game' % INITIAL_WAIT)
    time.sleep(INITIAL_WAIT)

    while True:
        print('Exiting cryo')
        use()

        time.sleep(1)

        print('Re-entering cryo')
        use()

        delay = random.randrange(CRYO_PERIOD_MIN, CRYO_PERIOD_MAX + 1)
        print('Waiting for %d seconds in cryo' % delay)
        time.sleep(delay)


if __name__ == '__main__':
    main()