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简介：众所周知，准确度time.sleep取决于操作系统和计算负载。Windows 中的准确性非常差。

与/questions/17499837类似，方法可以使用该time.clock方法作为time.sleep. 这种方法会产生不必要的负载，影响系统中的其他模块。在进行模拟时这是不可取的。

为了减少忙于等待而不依赖于 的时间量time.sleep，一个类使用了该方法select.select并利用了 timeout 属性。请参见下面的代码：

from sys import platform as _platform
import time, select, socket

class HighResolutionTimeStamp():
    __init = time.clock()
    __base = time.time()

    def __init__(self):
        self.__fd = socket.socket()
        self.dtts = time.clock if _platform == 'win32' else time.time

    def __del__(self):
        self.__fd.close()

    def get_high_resolution_dt(self):
        return HighResolutionTimeStamp.__base + self.dtts() if _platform == 'win32' else time.time()

    def busy_wait(self, wait_time):
        currentTime = self.dtts()
        while (self.dtts() <= currentTime + wait_time):
            pass

    def sleep(self, wait_time):
        currentTime = self.dtts()
        while (self.dtts() < (currentTime + wait_time - 0.001)):
            select.select([self.__fd], [], [], 0.001)
        while (self.dtts() < currentTime + wait_time):
            select.select([self.__fd], [], [], 0.0)

if __name__ == '__main__':
    st = 1.0/80.0
    it = 10
    ts = 1

    time.sleep(ts)
    hrdr = HighResolutionTimeStamp()
    total = hrdr.get_high_resolution_dt()
    for i in range(it):
        hrdr.busy_wait(st)
    print 'Ellapsed:', hrdr.get_high_resolution_dt() - total

    time.sleep(ts)
    total = hrdr.get_high_resolution_dt()
    for i in range(it):
        hrdr.sleep(st)
    print 'Ellapsed:', hrdr.get_high_resolution_dt() - total

    time.sleep(ts)
    total = hrdr.get_high_resolution_dt()
    for i in range(it):
        time.sleep(st)
    print 'Ellapsed:', hrdr.get_high_resolution_dt() - total

环境：我正在使用 PortablePython2.7.6.1

问题：当代码在 PyScripter 或在后台打开 PyScripter 的命令行中执行时，上面的脚本执行得非常准确。一旦 PyScripter 关闭，方法 sleep 就会变得不准确。我知道超时select.select应该是不准确的，time.sleep但在所有情况下，都不是如上所述。

结果：

没有在后台运行 PyScripter

C:\..\PortablePython2.7.6.1\App\python.exe highresolutiondt.py

Busy wait. Ellapsed: 0.125249385834

Sleep. Ellapsed: 0.15624165535

Time.sleep. Ellapsed: 0.156844139099

PyScripter 在后台运行

C:\..\PortablePython2.7.6.1\App\python.exe highresolutiondt.py

Busy wait. Ellapsed: 0.125702142715

Sleep. Ellapsed: 0.125874519348

Time.sleep. Ellapsed: 0.120799064636
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1 回答 1

1

This uses time since unix epoch, which, I'm pretty sure is more accurate, I don't use windows though, so I didn't test this out.

from time import time

def pause(secs):
    init_time = time()
    while time() < init_time+secs: pass

print("See ya in 10 seconds")
pause(10)
print("Heeeeeelooooo there")

Hope it helped

于 2020-07-03T17:11:54.150 回答