Python subprocess quick reference guide

subprocess.md

Python subprocess quick reference guide

Some methods for running shell commands from within Python, depending on what the expected behavior and desired output are.

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Popen

class subprocess.Popen(args, bufsize=- 1, executable=None, stdin=None, stdout=None, stderr=None, preexec_fn=None, close_fds=True, shell=False, cwd=None, env=None, universal_newlines=None, startupinfo=None, creationflags=0, restore_signals=True, start_new_session=False, pass_fds=(), *, group=None, extra_groups=None, user=None, umask=- 1, encoding=None, errors=None, text=None, pipesize=- 1)

Master class instantiated by the following functions.

run

func subprocess.run(args, *, stdin=None, input=None, stdout=None, stderr=None, capture_output=False, shell=False, cwd=None, timeout=None, check=False, encoding=None, errors=None, text=None, env=None, universal_newlines=None, **other_popen_kwargs)

General-purpose function for running commands. Return value is a CompletedProcess with attributes depending on the function's arguments.

call

func subprocess.call(args, *, stdin=None, stdout=None, stderr=None, shell=False, cwd=None, timeout=None, **other_popen_kwargs)

Runs the command, then returns simply the returncode.

check_call

func subprocess.check_call(args, *, stdin=None, stdout=None, stderr=None, shell=False, cwd=None, timeout=None, **other_popen_kwargs)

Same as call, but raises an error if returncode != 0.

check_output

func subprocess.check_output(args, *, stdin=None, stderr=None, shell=False, cwd=None, encoding=None, errors=None, universal_newlines=None, timeout=None, text=None, **other_popen_kwargs)

Runs command, returns output, raises an error if returncode != 0.

getoutput

func subprocess.getoutput(cmd)

Return output (stdout and stderr) alone.