Key input that does not wait for key input in Python

import fcntl
import termios
import sys
import os

def getkey():
    fno = sys.stdin.fileno()

    #Get stdin terminal attributes
    attr_old = termios.tcgetattr(fno)

    #Stdin echo disabled, canonical mode disabled
    attr = termios.tcgetattr(fno)
    attr[3] = attr[3] & ~termios.ECHO & ~termios.ICANON # & ~termios.ISIG
    termios.tcsetattr(fno, termios.TCSADRAIN, attr)

    #Set stdin to NONBLOCK
    fcntl_old = fcntl.fcntl(fno, fcntl.F_GETFL)
    fcntl.fcntl(fno, fcntl.F_SETFL, fcntl_old | os.O_NONBLOCK)

    chr = 0

    try:
        #Get the key
        c = sys.stdin.read(1)
        if len(c):
            while len(c):
                chr = (chr << 8) + ord(c)
                c = sys.stdin.read(1)
    finally:
        #Undo stdin
        fcntl.fcntl(fno, fcntl.F_SETFL, fcntl_old)
        termios.tcsetattr(fno, termios.TCSANOW, attr_old)

    return chr

if __name__ == "__main__":
    while 1:
        key = getkey()
        #Exit with enter, display if there is a key input
        if key == 10:
            break
        elif key:
            print(key)

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