[在Python psutil中调用函数时如何监视CPU的使用情况？

Question

嘿，我正在学习psutil软件包，我想知道在函数运行过程中如何显示当前的CPU使用情况？我想我需要一些线程或类似的东西，但是该怎么做呢？谢谢你的回答。

import psutil
import random

def iHateThis():
    tab = []
    for i in range(100000):
        tab.append(random.randint(1, 10000))

    tab.sort()
    return tab;

while(True):
    currentProcess = psutil.Process()
    print(currentProcess.cpu_percent(interval=1))

Answer 1

您可以使用multiprocessing库执行此操作。 multiprocessing.Process是一个代表线程处理的类，由函数和名称启动，可以随时通过.start()运行。

import multiprocessing
import psutil
import random

def iHateThis():
    tab = []
    for i in range(100000):
        tab.append(random.randint(1, 10000))
    tab.sort()
    return tab;

hate = multiprocessing.Process(name='hate', target=iHateThis)
hate.start()

while(True):
    currentProcess = psutil.Process()
    print(currentProcess.cpu_percent(interval=1))

Answer 2

您可以使用threading运行iHateThis或使用cpu_percent()运行功能。我选择第二个版本。我将在线程中运行cpu_percent()。

因为它使用while True，所以线程将永远运行，并且没有很好的方法来停止线程，所以我将全局变量running与while running一起使用来停止该循环。

import threading
import psutil

def display_cpu():
    global running

    running = True

    currentProcess = psutil.Process()

    # start loop
    while running:
        print(currentProcess.cpu_percent(interval=1))

def start():
    global t

    # create thread and start it
    t = threading.Thread(target=display_cpu)
    t.start()

def stop():
    global running
    global t

    # use `running` to stop loop in thread so thread will end
    running = False

    # wait for thread's end
    t.join()

现在我可以用它来启动和停止显示CPU的线程。因为我可能必须使用Ctrl+C停止进程，所以它会引发错误，因此即使有错误，我也会使用try/finally来停止线程。

def i_hate_this():
    tab = []
    for i in range(1000000):
        tab.append(random.randint(1, 10000))
    tab.sort()
    return tab

# ---

start()
try:
    result = i_hate_this()
finally: # stop thread even if I press Ctrl+C
    stop()

---

完整代码：

import random
import threading
import psutil

def display_cpu():
    global running

    running = True

    currentProcess = psutil.Process()

    # start loop
    while running:
        print(currentProcess.cpu_percent(interval=1))

def start():
    global t

    # create thread and start it
    t = threading.Thread(target=display_cpu)
    t.start()

def stop():
    global running
    global t

    # use `running` to stop loop in thread so thread will end
    running = False

    # wait for thread's end
    t.join()

# ---

def i_hate_this():
    tab = []
    for i in range(1000000):
        tab.append(random.randint(1, 10000))
    tab.sort()
    return tab

# ---

start()
try:
    result = i_hate_this()
finally: # stop thread even if I press Ctrl+C
    stop()

---

BTW：可以将其转换为继承自Thread类的类，然后可以将变量running隐藏在类中。

import psutil
import random
import threading

class DisplayCPU(threading.Thread):

    def run(self):

        self.running = True

        currentProcess = psutil.Process()

        while self.running:
            print(currentProcess.cpu_percent(interval=1))

    def stop(self):
        self.running = False

# ----

def i_hate_this():
    tab = []
    for i in range(1000000):
        tab.append(random.randint(1, 10000))
    tab.sort()
    return tab

# ---

display_cpu = DisplayCPU()

display_cpu.start()
try:
    result = i_hate_this()
finally: # stop thread even when I press Ctrl+C
    display_cpu.stop()

---

它也可以转换成上下文管理器以运行它，>]

with display_cpu():
    i_hate_this()
但是我跳过了这一部分。