如何使此计时器永远运行? [英] How can I make this timer run forever?

问题描述

from threading import Timer

def hello():
    print "hello, world"

t = Timer(30.0, hello)
t.start()

此代码仅触发一次计时器.

This code only fires the timer once.

如何使计时器永远运行?

How can I make the timer run forever?

谢谢

已更新

这是正确的:

import time,sys

def hello():
    while True:
        print "Hello, Word!"
        sys.stdout.flush()
        time.sleep(2.0)
hello()

和这个:

from threading import Timer

def hello():
    print "hello, world"
    sys.stdout.flush()
    t = Timer(2.0, hello)
    t.start()

t = Timer(2.0, hello)
t.start()

推荐答案

threading.Timer一次执行函数 .如果您愿意，该功能可以永远运行"，例如:

A threading.Timer executes a function once. That function can "run forever" if you wish, for example:

import time

def hello():
    while True:
        print "Hello, Word!"
        time.sleep(30.0)

使用多个Timer实例将消耗大量资源，而没有真正的附加值.如果您希望每30秒重复一次此功能，那么一种简单的方法是:

Using multiple Timer instances would consume substantial resources with no real added value. If you want to be non-invasive to the function you're repeating every 30 seconds, a simple way would be:

import time

def makerepeater(delay, fun, *a, **k):
    def wrapper(*a, **k):
        while True:
            fun(*a, **k)
            time.sleep(delay)
    return wrapper

，然后安排makerepeater(30, hello)而不是hello.

对于更复杂的操作，我建议使用标准库模块 sched .

For more sophisticated operations, I recommend standard library module sched.

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