Feature or enhancement

Proposal:

types.SimpleNamespace is a lightweight object for grouping attributes. However, it lacks a built-in way to update multiple attributes at once using keyword arguments.

Currently, users must write:

ns.__dict__.update({'x': 1, 'y': 2})

This leaks implementation details and reduces code clarity. A built-in method would make this cleaner and more idiomatic.

Add an update(**kwargs) method to SimpleNamespace that updates the namespace in place:

from types import SimpleNamespace

ns = SimpleNamespace(a=1)
ns.update(b=2, c=3)
print(ns)  # namespace(a=1, b=2, c=3)

• Implemented in Objects/namespaceobject.c

• Calls PyDict_Update(self->dict, kwargs) directly

• Uses the --\n\n signature string convention so inspect.signature() works

• Added test in Lib/test/test_types.py

Benchmarks:
Measured over 1 million repetitions:

SimpleNamespace.update() | 1.25 s
dict.update() | 1.10 s
class().attr = value | 0.55 s

Testing:
Unit test confirms that update() modifies or adds attributes correctly

inspect.signature(SimpleNamespace.update) returns a valid signature

Full CPython test suite run — no regressions introduced

Has this already been discussed elsewhere?

I have already discussed this feature proposal on Discourse

Links to previous discussion of this feature:

https://discuss.python.org/t/update-method-for-simplenamespace/97207

Linked PRs

• gh-136140: Add update(**kwargs) method to types.SimpleNamespace #136142