如何无限期地在 Python 中重复命令 [英] How to repeat command in Python indefinitely

问题描述

我这里有一个脚本，假设使用命令来输出 RPi 的温度.

I have a script here that is suppose to use a command to output the temperature of a RPi.

from tkinter import *
import subprocess

win = Tk()

f1 = Frame( win )

while True:
    output = subprocess.check_output('/opt/vc/bin/vcgencmd measure_temp', shell=True)

tp = Label( f1 , text='Temperature: ' + str(output[:-1]))

f1.pack()

tp.pack()

win.mainloop()

因为我想看到温度变化，所以我试图让命令重复，但它破坏了脚本.如何让命令重复，以便我可以不断更新温度?

Since I want to see the temperature change, I tried to make the command repeat itself but it breaks the script. How can I make the command repeat itself so I can have constantly updating temperature?

推荐答案

您可以使用 Tk.after() 方法定期运行您的命令.在我的 PC 上，我没有温度传感器，但我有一个时间传感器.此程序每 2 秒更新一次显示的新日期:

You can use the Tk.after() method to run your command periodically. On my PC, I don't have a temperature sensor, but I do have a time sensor. This program updates the display every 2 seconds with a new date:

from tkinter import *
import subprocess

output = subprocess.check_output('sleep 2 ; date', shell=True)

win = Tk()
f1 = Frame( win )
tp = Label( f1 , text='Date: ' + str(output[:-1]))
f1.pack()
tp.pack()

def task():
    output = subprocess.check_output('date', shell=True)
    tp.configure(text = 'Date: ' + str(output[:-1]))
    win.after(2000, task)
win.after(2000, task)

win.mainloop()

参考:你如何运行你的自己的代码和 Tkinter 的事件循环?

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