context-compose 0.0.2

Compose context managers from a sequence

context_compose

Python utility library to compose context managers (3.6+)

Motivation

When you want to use a dynamic combination of context managers together, and the builtin ways are too ugly or inflexible.

Turn this:

import os

if __name__ == "__main__":
    if os.environ.get("DEBUG") and os.environ.get("PROFILE":
        with debugger(), profile():
            main()
    elif os.environ.get("DEBUG"):
        with debugger():
            main()
    elif os.environ.get("DEBUG"):
        with debugger():
            main()

Into this:

import os

from context_compose import compose, impotent_manager


if __name__ == "__main__":
    managers = [
        debugger() if os.environ.get("DEBUG") else impotent_manager(),
        profile() if os.environ.get("PROFILE") else impotent_manager(),
    ]
    with compose(managers):
        main()

impotent_manager is a useful substitute when your code has a with block, you'd rather keep to a single pattern so a context manager must be provided to it.

How it works

Under the hood it uses contextlib.ExitStack to layer context managers in list order.