How to get current CPU and RAM usage in Python?

Use the psutil library. On Ubuntu 18.04, pip installed 5.5.0 (latest version) as of 1-30-2019. Older versions may behave somewhat differently. You can check your version of psutil by doing this in Python:

from __future__ import print_function  # for Python2
import psutil
print(psutil.__versi‌​on__)

To get some memory and CPU stats:

from __future__ import print_function
import psutil
print(psutil.cpu_percent())
print(psutil.virtual_memory())  # physical memory usage
print('memory % used:', psutil.virtual_memory()[2])

The virtual_memory (tuple) will have the percent memory used system-wide. This seemed to be overestimated by a few percent for me on Ubuntu 18.04.

You can also get the memory used by the current Python instance:

import os
import psutil
pid = os.getpid()
python_process = psutil.Process(pid)
memoryUse = python_process.memory_info()[0]/2.**30  # memory use in GB...I think
print('memory use:', memoryUse)

which gives the current memory use of your Python script.

There are some more in-depth examples on the pypi page for psutil.

The psutil library gives you information about CPU, RAM, etc., on a variety of platforms:

psutil is a module providing an interface for retrieving information on running processes and system utilization (CPU, memory) in a portable way by using Python, implementing many functionalities offered by tools like ps, top and Windows task manager.

It currently supports Linux, Windows, OSX, Sun Solaris, FreeBSD, OpenBSD and NetBSD, both 32-bit and 64-bit architectures, with Python versions from 2.6 to 3.5 (users of Python 2.4 and 2.5 may use 2.1.3 version).

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Some examples:

#!/usr/bin/env python
import psutil
# gives a single float value
psutil.cpu_percent()
# gives an object with many fields
psutil.virtual_memory()
# you can convert that object to a dictionary 
dict(psutil.virtual_memory()._asdict())
# you can have the percentage of used RAM
psutil.virtual_memory().percent
79.2
# you can calculate percentage of available memory
psutil.virtual_memory().available * 100 / psutil.virtual_memory().total
20.8

Here's other documentation that provides more concepts and interest concepts:

• https://psutil.readthedocs.io/en/latest/

Only for Linux: One-liner for the RAM usage with only stdlib dependency:

import os
tot_m, used_m, free_m = map(int, os.popen('free -t -m').readlines()[-1].split()[1:])

One can get real time CPU and RAM monitoring by combining tqdm and psutil. It may be handy when running heavy computations / processing.

It also works in Jupyter without any code changes:

from tqdm import tqdm
from time import sleep
import psutil

with tqdm(total=100, desc='cpu%', position=1) as cpubar, tqdm(total=100, desc='ram%', position=0) as rambar:
    while True:
        rambar.n=psutil.virtual_memory().percent
        cpubar.n=psutil.cpu_percent()
        rambar.refresh()
        cpubar.refresh()
        sleep(0.5)

It's convenient to put those progress bars in separate process using multiprocessing library.

This code snippet is also available as a gist.