ok-subprocess-runner 0.3

Wrapper for subprocess.run() with defaults and logging

ok-subprocess-runner for Python

Trivial wrapper for Python subprocess.run with defaults and logging.

You probably won't want to use this. Just call subprocess.run directly (it's perfectly lovely), write your own trivial helper, or use one of these libraries:

• sh - call any shell command as if it were a function
• Plumbum - shell-like syntax for Python
• zxpy - ~ string operator to run shell commands
• shellpy - ``` string operator to run shell commands
• shell - another wrapper for subprocess
• pipepy - pipe operators and function wrappers for shell commands
• python-shell - another shell command runner

But, this is my wrapper, and it does these things:

• Checks command return (check=True) by default
• Uses explicit argument vectors (shell=False) by default
• Includes easy-peasy methods to capture stdout as text or lines
• Logs all commands run, escaped for cut-and-paste rerunning
• Lets you set defaults for cwd and env (merged with os.environ)
• Converts Path-like arguments to strings
• Passes extra keyword arguments through to subprocess.run

Collectively, this is what I want for subprocesses -- tweaks to subprocess.run (or subprocess.check_call) to make it super easy to never write shell scripts again. Your mileage will almost certainly vary!

Usage

Add this package as a dependency:

• pip install ok-subprocess-runner
• OR just copy the ok_subprocess_runner/ module (it has no dependencies)

Import the module, create an ok_subprocess_runner.SubprocessRunner object, and call it to run commands:

import logging
import ok_subprocess_runner
...
sub = ok_subprocess_runner.SubprocessRunner()
...
logging.basicConfig(level=logging.INFO)  # to show the logging
...
sub("echo", "Hello World!")

Command arguments are individual function arguments; otherwise, usage is identical to subprocess.run including keyword arguments and return value.

The logging output looks like this:

$ python test.py
INFO:root:🐚 echo 'Hello World!'
Hello World!

Note that arguments are escaped so you can cut-and-paste the command.

Configuring defaults

SubprocessRunner objects have properties that set defaults:

• .args_prefix (list of string or Path-like) - prepended to all commands run
• .check (bool) - default for check arg (default true)
• .cwd (string or Path-like) - default for cwd arg (default empty)
• .env (string dict) - merged with os.environ as default env arg
• .log_level (int) - level for command logging (default logging.INFO)

Capturing output

SubprocessRunner objects have some utility wrappers to capture output:

• .stdout_text(args, ...) - returns captured stdout as a text string
• .stdout_lines(args, ...) - returns captured stdout split into lines

Pass-through

All calls pass keyword arguments through to subprocess.run.

sub = ok_subprocess_runner.SubprocessRunner()
sub("echo", "Hello World!", check=False, cwd="/tmp", env={"FOO": "BAR"})