persishell 0.1.0

A simple wrapper around subprocess with persistent environment variables

persishell

Lightweight replacement for os.system() with a persistent environment.

persishell is a simple Python library that wraps a persistent Bash subprocess, allowing you to run shell commands sequentially — with shared environment state across runs. It's useful when you need to maintain exported variables, cd into directories, interact with module load, or configure shell settings once and use them across multiple commands.

I use it extensively on SLURM clusters to write all my experiment scripts (including the sbatch scripts) in Python.

Installation

pip install persishell

Or for development:

pip install -e .

Quick Start

from persishell import PersiShell

sh = PersiShell()

# Set environment variables
sh.export("FOO", "bar")

# Commands use the persistent environment
sh.run("echo $FOO")  # prints: bar

# Change directories
sh.run("cd /tmp")
sh.run("pwd")  # prints: /tmp

# Unset environment variables
sh.unset("FOO")
sh.run("echo $FOO")  # prints an empty line

API Summary

PersiShell.run(command: str | list, optinal arguments)

Run a command inside the persistent shell. Accepts a string or a list of arguments.

PersiShell.export(key: str, value: str)

Export a persistent environment variable.

PersiShell.unset(key: str)

Unset a previously defined environment variable.

Limitations

Currently designed for Unix-like systems (uses bash, fcntl). It has not been tested on Windows.

License

MIT License