Get CPU load in python on Raspberry Pi doesn't work

Question

I have googled for code to get the CPU load on RPi3. I found this code:

import os

def getCPUuse():
    return str(os.popen("top -n1 | awk '/Cpu\(s\):/ {print $2}'").readline().strip())

For me it only returns an empty string.

Where is the problem in this code?

EDIT:

I call it like this:

while True:
    time.sleep(0.2)
    use = getCPUuse()
    print(use)

I'd suggest running `top -n1` on your Pi and see if the format you get back is what you expect in your awk regex. It may be a different version/configuration of top than your host, which may produce a different format. — Zrax, Dec 01 '17 at 18:28
It's working in my RPI. I might be mean but, are you calling your function with let's say `print getCPUuse()`? — silgon, Dec 01 '17 at 19:37
Does this `top -n1 | awk '/Cpu$s$:/ {print $2}'` produce correct data run in terminal? — user1767754, Dec 01 '17 at 19:50
No, but if I replace `top -n1 | awk ...` by `top -n1` nothing happnes as well, it only prints empty lines — monamona, Dec 01 '17 at 20:48
why not just install python module psutil which has functions for reading cpu usage? — DisappointedByUnaccountableMod, Dec 03 '17 at 10:17

score 1 · Accepted Answer · edited May 29 '20 at 16:10

1

Take off the strip() and just do readline. That worked for me.

edited May 29 '20 at 16:10

Yunnosch

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answered May 29 '20 at 16:04

starke1981

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This one-liner (actually only half of the line) seems to be an actual though short attempt to answer. Thanks for your contribution. However, if you could add some explanation of how your proposed solution works and why it is supposed to help - that would make it more convincing and helpful. – Yunnosch May 29 '20 at 16:09

score 1 · Answer 2 · answered Nov 15 '20 at 21:53

You can use the gpiozero module - it comes pre-installed with Raspberry Pi OS. So you can use this code, it is a bit easier to read too (in my opinion):

from gpiozero import LoadAverage

print(str(int(LoadAverage(minutes=1).load_average*100))+"%")

EDIT: This link may help: https://gpiozero.readthedocs.io/en/stable/api_internal.html#loadaverage

Get CPU load in python on Raspberry Pi doesn't work

2 Answers2