subprocess.CalledProcessError: Command 'df' returned non-zero exit status 1-CodePudding

stackoverflow community!

I use python3 to collect some information from a server, but I had this Error and I did not find a solution for it.

This is my code below :

from subprocess import check_output
disks = check_output(("df")).decode("utf-8").split('\n')
print(disks)

and this is the output:

df: /run/user/1001/doc: Operation not permitted
Traceback (most recent call last):
  File "<stdin>", line 2, in <module>
  File "/usr/lib/python3.9/subprocess.py", line 424, in check_output
    return run(*popenargs, stdout=PIPE, timeout=timeout, check=True,
  File "/usr/lib/python3.9/subprocess.py", line 528, in run
    raise CalledProcessError(retcode, process.args,
subprocess.CalledProcessError: Command 'df' returned non-zero exit status 1.

check_output() it work with other commands for example: check_output(("uname")).decode("utf-8") the output is: Linux

Why it work with other commands, but it don't work with df command? and what is the solution for this problem?

the command df it work when I run it from the terminal

CodePudding user response：

Your Python code is fine as such. If you want to avoid the traceback, subprocess.run lets you do that.

from subprocess import run
disks = run(["df"], capture_output=True, text=True)
print(disks.stdout)

The check in check_output means specifically that Python will raise an error if the subprocess fails. But Python is not doing anything useful here. Simply

import subprocess
subprocess.call(["df"])

would do the same thing with less hassle. (Running df without Python would obviously be more straightforward still.)

CodePudding user response：

It looks like you have a permissions error. You could probably get a better error indication by doing that directly in Python. The following function does the equivalent.

import os


def df(path="/"):
    """Return file system blocks used and free.

    Values are same as output of df command.
    """
    stat = os.statvfs(path)
    return (((stat.f_blocks - stat.f_bfree) * 8),
            (stat.f_bavail * (stat.f_frsize // 512)))