All-in-one function to execute command-line programs through python

shex.py

#!/usr/bin/env python3
'''
Execute "simple" (non-daemon) command-line programs through python, for use in python shell scripts.
Rationale: Python scripting seems more fun than bash scripting.
WARNING: Use at your own risk. I am not liable for the destruction of your system.
'''

from typing import Tuple
import os, shlex
from subprocess import PIPE, Popen, CalledProcessError

env = os.environ.copy()


def sh_execute(command: str) -> Tuple[str, str]:
    if not command:
        raise Exception('No command provided.')
    if '~' in command:
        command = command.replace('~', os.path.expanduser('~'))
    args = shlex.split(command)
    pipes = Popen(args, stdout=PIPE, stderr=PIPE, env=env)
    stdout, stderr = pipes.communicate()
    out, err = stdout.decode(), stderr.decode()
    if pipes.returncode != 0:
        raise ShError(pipes.returncode, args, output=out, stderr=err)
    return out, err


shex = sh_execute


class ShError(CalledProcessError):
    """Raised when sh_execute() is called and the process
    returns a non-zero exit status.

    Attributes:
      cmd, returncode, stdout, stderr, output
    """
    pass


def pshex(command: str) -> None:
    ''' Execute and then print the output of sh_execute. '''
    try:
        out, err = sh_execute(command)
    except ShError as err:
        print(err.stderr, end='', flush=True)
    else:
        if err:
            print(err, end='', flush=True)
        if out:
            print(out, end='', flush=True)


# For testing on the command line:
if __name__ == '__main__':
    import sys

    command = ' '.join(sys.argv[1:])
    pshex(command)