cpu_percent(interval = None)始终返回0，与间隔值PYTHON无关 [英] cpu_percent(interval=None) always returns 0 regardless of interval value PYTHON

问题描述

无论间隔值如何，代码始终返回0.0值.

The code always returns 0.0 values, regardless of interval values.

import psutil
p = psutil.Process()
print p.cpu_percent(interval=1)
print p.cpu_percent(interval=None)

推荐答案

此行为已记录:

当时间间隔为0.0或None时，会将处理时间与自上次调用以来经过的系统CPU时间进行比较，并立即返回.这意味着第一次调用它会返回一个无意义的0.0值，您应该忽略它.在这种情况下，为确保准确性，建议第二次调用该函数，两次调用之间的间隔至少为0.1秒.

When interval is 0.0 or None compares process times to system CPU times elapsed since last call, returning immediately. That means the first time this is called it will return a meaningless 0.0 value which you are supposed to ignore. In this case is recommended for accuracy that this function be called a second time with at least 0.1 seconds between calls.

还有一个警告，禁止在单个呼叫中使用interval=None:

There is also a warning against using interval=None for a single call:

警告::第一次使用 interval = 0.0或None调用此函数时，它将返回一个无意义的0.0值，您应该该值忽略.

Warning: the first time this function is called with interval = 0.0 or None it will return a meaningless 0.0 value which you are supposed to ignore.

如果使用interval=None，请确保与以前的呼叫相比要呼叫.cpu_percent.

If using interval=None, make sure to call .cpu_percent compared to a prior call.

p = psutil.Process(pid=pid)
p.cpu_percent(interval=None)
for i in range(100):
    usage = p.cpu_percent(interval=None)
    # do other things

代替:

for i in range(100):
    p = psutil.Process(pid=pid)
    p.cpu_percent(interval=None)
    # do other things

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