# Ownership and cleanup

Source: https://libtmux.org/en/py/stable/topics/context-managers/

> Scope-based cleanup for tmux objects, and when your program must kill them explicitly.

A tmux session, window, or pane normally remains until you kill it. Scope-based
cleanup can kill it when your code leaves a block, including after an exception.
See [Workspaces](https://libtmux.org/en/py/stable/concepts/workspaces/) for a temporary layout example.

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## Nested context managers

Python's [`Server`](<https://libtmux.org/en/py/stable/reference/libtmux-server/>), [`Session`](<https://libtmux.org/en/py/stable/reference/libtmux-session/>), [`Window`](<https://libtmux.org/en/py/stable/reference/libtmux-window/>), and [`Pane`](<https://libtmux.org/en/py/stable/reference/libtmux-pane/>) support context managers.
Entry returns the existing object; exit kills it, including when the block
raises:

```python
with Server() as server:
    with server.new_session() as session:
        with session.new_window() as window:
            with window.split() as pane:
                pane.send_keys('echo "Hello"')
                # everything above is killed on the way out, in reverse order
```

Nested scopes exit in reverse order: pane, window, session, then server.

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## Testing cleanup

Use explicit cleanup for objects whose handles have no disposal hook. For an
entire disposable test server, prefer your port's test fixture or server guard;
see [Testing with libtmux](https://libtmux.org/en/py/stable/guides/testing-with-libtmux/).