我正在编写一个计时器程序，该程序具有重新启动，暂停或停止计时器的功能

Question

The problem that I am having is figuring out how to retrieve a time value from the broken timer() while loop and store it into the begintimer() function which would have a prompt section at the end of it which is the {/* implementation not shown */} segment.

import time
import sys


def timer(seconds, minutes, hours):
    time_start = time.time()
    seconds = 0
    minutes = 0
    hours = 0
    print("\n")
    print(time.time())
    print("seconds since the python epoch.\n")
    while True:
        sys.stdout.write("\r{hours}:{minutes}:{seconds}".format(hours=hours, minutes=minutes, seconds=seconds))
        time.sleep(1)
        seconds = int(time.time() - time_start) - minutes * 60
        if seconds >= 60:
            minutes += 1
            if minutes >= 60:
                hours += 1
                minutes = 0
            seconds = 0
        yield (seconds, minutes, hours)



def stopwatch():
    keep_running = 0
    while keep_running == 0:
        user_response = raw_input("Start?")
    if user_response in ["y", "yes", "Y", "YES", "Yes", "1", 1]:
            keep_running = begintimer(0,0,0)
    if user_response in ["n", "no", "N", "NO", "No", "0", 0]:
        keep_running = 2

def begintimer(sec, min, hou):
    sec = 0
    min = 0
    hou = 0
    sec, min, hou = timer(sec, min, hou)
    {/* implementation not shown */}

stopwatch()

Answer 1

A simple hack that you could do is to use at try to catch a KeyboardInterruption

Time = 0
while True:
    try:
        t1 = time.time()
        **more code**
    except KeyboardInterruption: # use Ctrl + c to pause
        t2 = time.time()
        Time += t2 - t1
         ** query desire**
         if user_wants_to_continue:
            continue
         else:
            break

Answer 2

The "Start?" prompt in stopwatch() is in an infinite loop since keep_running's value isn't being changed when you call raw_input. Indenting the rest of the function will allow the rest of the code to run:

def stopwatch():
    keep_running = 0
    while keep_running == 0:
        user_response = raw_input("Start?")
        if user_response in ["y", "yes", "Y", "YES", "Yes", "1", 1]:
            keep_running = begintimer(0,0,0)
        if user_response in ["n", "no", "N", "NO", "No", "0", 0]:
            keep_running = 2

You also have an infinite loop in timer(). The final yield call isn't enough to change the loop condition from True to False. There needs to be a condition in that loop that allows you to escape it. You can also return the tuple instead of yielding it.

def timer(seconds, minutes, hours):
    time_start = time.time()
    seconds = 0
    minutes = 0
    hours = 0
    print("\n")
    print(time.time())
    print("seconds since the python epoch.\n")
    while True:
        sys.stdout.write("\r{hours}:{minutes}:{seconds}".format(hours=hours, minutes=minutes, seconds=seconds))
        time.sleep(1)
        seconds = int(time.time() - time_start) - minutes * 60
        if seconds >= 60:
            minutes += 1
            if minutes >= 60:
                hours += 1
                minutes = 0
            seconds = 0
        # escape condition
        if seconds >= 5:
            break
    return (seconds, minutes, hours)

Answer 3

This is your code refactored to work. Functions that use the keyword yield return generators. The datetime module has classes suitable for this type of thing.

Code:

import datetime
import time

def timer_gen(hours = 0, minutes = 0, seconds = 0):
    time_start = datetime.datetime.now()
    duration   = datetime.timedelta\
    (
        hours   = hours,
        minutes = minutes,
        seconds = seconds,
    )
    time_diff = datetime.datetime.now() - time_start
    while time_diff < duration:
        time_diff = datetime.datetime.now() - time_start
        hours  , remainder = divmod(int(time_diff.total_seconds()), 60*60)
        minutes, seconds   = divmod(remainder, 60)
        yield (hours, minutes, seconds)

def stopwatch():
    keep_running = 0
    while keep_running == 0:
        user_response = raw_input("Start?")
        if user_response in ["y", "yes", "Y", "YES", "Yes", "1", 1]:
                keep_running = begintimer(0, 0, 5)
        if user_response in ["n", "no", "N", "NO", "No", "0", 0]:
            keep_running = 2

def begintimer(hours = 0, minutes = 0, seconds = 0):
    timer = timer_gen(hours, minutes, seconds)

    for (hours, minutes, seconds) in timer:
        print('{} hrs {} mins {} secs'.format(hours, minutes, seconds))
        time.sleep(1)

stopwatch()

In any case, there are modules written that already do this .