Stopwatch in python? Count until you press space

Question

I want to make a stopwatch in python 3.3 that continues to count until you press a button or something, it should then stop counting. This is my code:

seconds = 0
minutes = 0
continued = 0
while continued != 1:
    print(minutes, ":", seconds)
    time.sleep(1)
    if seconds == 59:
        seconds = 0
        minutes = minutes + 1
    else:
        seconds = seconds + 1

without using CTRL + C

I am using no GUI or anything, just pure python code running in command prompt using IDLE.

Answer 1

Attempting to waiti for a keypress in a loop, without threading or timers/signals will block the loop.

One way to have the main loop continue processing (stopwatch) while waiting for a keypress is via threading. A preliminary search brought me to an ActiveState recipe, although I found the solution from this thread.

import threading, os, time, itertools, queue

try : # on windows
    from msvcrt import getch
except ImportError : # on unix like systems
    import sys, tty, termios
    def getch() :
        fd = sys.stdin.fileno()
        old_settings = termios.tcgetattr(fd)
        try :
            tty.setraw(fd)
            ch = sys.stdin.read(1)
        finally :
            termios.tcsetattr(fd, termios.TCSADRAIN, old_settings)
        return ch

commands = queue.Queue(0)

def control(commands) :

    while 1 :

        command = getch()
        commands.put(command) # put the command in the queue so the other thread can read it

        #  don't forget to quit here as well, or you will have memory leaks
        if command == " " :
            print "Stop watch stopped!"
            break

def display(commands):
    seconds = 0
    minutes = 0

    command = ""

    while 1 :

        # parsing the command queue
        try:
           # false means "do not block the thread if the queue is empty"
           # a second parameter can set a millisecond time out
           command = commands.get(False) 
        except queue.Empty, e:
           command = ""

        # behave according to the command
        if command == " " :
            break

        print(minutes, ":", seconds, end="")

        if seconds == 59:
            seconds = 0
            minutes = minutes + 1
        else:
            seconds = seconds + 1
        time.sleep(1)


# start the two threads
displayer = threading.Thread(None,display,None, (commands,),{})

controler = threading.Thread(None, control, None, (commands,), {})

if __name__ == "__main__" :
    displayer.start()
    controler.start()