Can an app state instance be removed?

[dineshbvadhia]

app.state.stuff = do_stuff()

Is it possible to remove (delete) the instance stuff from app.state?

[s-chudmunge]

Yes, you can remove attributes from app.state using standard Python del or delattr():

# Using attribute syntax
del app.state.stuff

# Or dynamically with delattr
delattr(app.state, "stuff")

Under the hood, Starlette's State class stores attributes inside an internal dictionary _state and implements __delattr__ (as well as __delitem__):

def __delattr__(self, key: Any) -> None:
    del self._state[key]

After deletion:

• Accessing app.state.stuff will raise AttributeError: 'State' object has no attribute 'stuff'
• hasattr(app.state, 'stuff') returns False

If you try to delete an attribute that doesn't exist, it will raise a standard KeyError (from the underlying dict), so if the attribute might not be present, you can guard it with:

if hasattr(app.state, "stuff"):
    del app.state.stuff