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.

so what is the problem? it will run until you kill it with + — Facundo Casco, Jan 18 '13 at 14:19
Using no gui or anything, pure python code using IDLE that runs in command prompt — user1836262, Jan 18 '13 at 14:23
See this question http://stackoverflow.com/questions/5044073/python-cross-platform-listening-for-keypresses — Facundo Casco, Jan 18 '13 at 14:27
What OS? This is better done using an OS timer, or simply use the difference between the time of day before and after the key press. — Keith, Jan 18 '13 at 18:04

score 3 · Answer 1 · edited May 23 '17 at 11:54

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()

Noctis Skytower · Answer 2 · 2013-01-21T22:15:34.477

If you want a GUI for your stopwatch, you might be interested in the following code meant for Python 3.x.

#! /usr/bin/env python3
import tkinter
import time

class StopWatch(tkinter.Frame):

    @classmethod
    def main(cls):
        tkinter.NoDefaultRoot()
        root = tkinter.Tk()
        root.title('Stop Watch')
        root.resizable(True, False)
        root.grid_columnconfigure(0, weight=1)
        padding = dict(padx=5, pady=5)
        widget = StopWatch(root, **padding)
        widget.grid(sticky=tkinter.NSEW, **padding)
        root.mainloop()

    def __init__(self, master=None, cnf={}, **kw):
        padding = dict(padx=kw.pop('padx', 5), pady=kw.pop('pady', 5))
        super().__init__(master, cnf, **kw)
        self.grid_columnconfigure(1, weight=1)
        self.grid_rowconfigure(1, weight=1)
        self.__total = 0
        self.__label = tkinter.Label(self, text='Total Time:')
        self.__time = tkinter.StringVar(self, '0.000000')
        self.__display = tkinter.Label(self, textvariable=self.__time)
        self.__button = tkinter.Button(self, text='Start', command=self.__click)
        self.__label.grid(row=0, column=0, sticky=tkinter.E, **padding)
        self.__display.grid(row=0, column=1, sticky=tkinter.EW, **padding)
        self.__button.grid(row=1, column=0, columnspan=2,
                           sticky=tkinter.NSEW, **padding)

    def __click(self):
        if self.__button['text'] == 'Start':
            self.__button['text'] = 'Stop'
            self.__start = time.clock()
            self.__counter = self.after_idle(self.__update)
        else:
            self.__button['text'] = 'Start'
            self.after_cancel(self.__counter)

    def __update(self):
        now = time.clock()
        diff = now - self.__start
        self.__start = now
        self.__total += diff
        self.__time.set('{:.6f}'.format(self.__total))
        self.__counter = self.after_idle(self.__update)

if __name__ == '__main__':
    StopWatch.main()

score 1 · Answer 3 · answered Jan 18 '13 at 20:01

Use curses:

import curses
from datetime import datetime

SPACE_KEY = ord(' ')

def run(win):
    curses.echo()
    win.timeout(1000) # Wait at most one second for a key.

    start = datetime.now()
    while True:
        now = datetime.now()
        minutes, seconds = divmod((now - start).total_seconds(), 60)
        win.addstr(0, 0, "%02d:%02d" % (minutes, round(seconds)))

        c = win.getch()
        if c == SPACE_KEY:
            break

curses.wrapper(run)

Under Windows this is a non-issue since you have kbhit and getch available in the msvcrt module.

Stopwatch in python? Count until you press space

3 Answers3

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