我需要使用一个可以暂停和恢复的计时器。据我所知，Python中只有一个计时器，它包含在threading包中，但我不能暂停或恢复它，只能取消它。
这是在Python中使用计时器的标准代码：
from threading import Timer
import time
def timeout():
print "Game over"
t = Timer(20 * 60, timeout)
t.start()
那么我应该怎么做才能用这个定时器实现暂停/恢复功能呢？
import threading, time
class ResumableTimer:
def __init__(self, timeout, callback):
self.timeout = timeout
self.callback = callback
self.timer = threading.Timer(timeout, callback)
self.startTime = time.time()
def start(self):
self.timer.start()
def pause(self):
self.timer.cancel()
self.pauseTime = time.time()
def resume(self):
self.timer = threading.Timer(
self.timeout - (self.pauseTime - self.startTime),
self.callback)
self.timer.start()
你的家庭作业：
- 继承
- 例外情况？支票
- 比可恢复计时器更好的东西
最终类发布
from threading import Timer
import time
class RenewableTimer:
def __init__(self, timeout, callback):
self.timer = Timer(timeout, callback)
self.start_time = None
self.cancel_time = None
# Used for creating a new timer upon renewal
self.timeout = timeout
self.callback = callback
def cancel(self):
self.timer.cancel()
def start(self):
# NOTE: erroneously calling this after pausing causes errors where
# start_time is updated, and then you get a RuntimeError
# for trying to restart a thread
self.start_time = time.time()
self.timer.start()
def pause(self):
self.cancel_time = time.time()
self.timer.cancel()
return self.get_remaining_time()
def resume(self):
self.timeout = self.get_remaining_time()
self.timer = Timer(self.timeout, self.callback)
self.start_time = time.time()
self.timer.start()
def get_remaining_time(self):
if self.start_time is None or self.cancel_time is None:
return self.timeout
return self.timeout - (self.cancel_time - self.start_time)
另一种需要考虑的方法是跟踪每个时段的时间；停止"；计时器，但实际上保持计时器运行。然后在任务结束时，只需从总运行时间中减去总暂停时间。
import keyboard
from timeit import default_timer as timer
elapsedPauseTime = 0;
print("'s' to start task timer")
print("'p' to pause task timer")
print("'r' to resume task timer")
print("'e' to end task timer")
while (1 == 1):
if keyboard.read_key() == "s":
print("Task Timer Started")
timerStart = timer()
if keyboard.read_key() == "p":
print("Task Timer pause counter started")
timerPauseStart = timer()
if keyboard.read_key() == "r":
print("Task Timer pause counter stopped")
timerPauseEnd = timer()
elapsedPauseTime = elapsedPauseTime + timerPauseEnd - timerPauseStart
if keyboard.read_key() == "e":
print("Task Timer Ended")
timerEnd = timer()
break
print("Total time: " + str(timerEnd - timerStart))
print("Pause time: " + str(elapsedPauseTime))
print("Task time with pauses: " + str(timerEnd - timerStart - elapsedPauseTime))