chore(python-sdk): modernise type hints

[stevenh]

Leverage future import annotations to enable support for streamlined type hints using | vs Union from PEP 604.

Future annotations was enabled across the codebase so that any additional use of Optional or Union would be flagged by type linters.

Removed unused imports, guarded import under TYPE_CHECKING where necessary.

Fixed accept parameter definition for EventEncoder and added a missing comment.

Fixes: #50

[Copilot]

Pull Request Overview

Modernize type hints across the Python SDK by enabling postponed evaluation of annotations, replacing Union/Optional with |, cleaning up imports, and tightening the EventEncoder initializer.

• Add from __future__ import annotations and use PEP 604 unions everywhere.
• Remove unused imports and guard imports under TYPE_CHECKING.
• Update EventEncoder.__init__ signature and add a basic docstring.

Reviewed Changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
python-sdk/tests/test_types.py	Added future annotations import for streamlined type hints.
python-sdk/tests/test_events.py	Added annotations import; removed unused json and Message.
python-sdk/tests/test_encoder.py	Added future annotations import.
python-sdk/ag_ui/encoder/encoder.py	Guarded event type import, updated __init__ signature and doc.
python-sdk/ag_ui/encoder/init.py	Added future annotations import.
python-sdk/ag_ui/core/types.py	Replaced Union/Optional with `
python-sdk/ag_ui/core/events.py	Replaced Optional[...] with `
python-sdk/ag_ui/core/init.py	Added future annotations import.

Comments suppressed due to low confidence (1)

python-sdk/ag_ui/encoder/encoder.py:20

• Expand this docstring to document the accept parameter (its purpose, valid values, and default behavior) to improve clarity for future readers.

"""
        Initializes the EventEncoder.
        """

[stevenh]

@NathanTarbert @mme could you have a look at this.

[stevenh]

This needs updating with all the changes, so switching it back to draft

[stevenh]

This won't be valid until 3.9 support is dropped, which is EOL October 2025

[tylerslaton]

Hi @stevenh we're just going back through old PR's - is this still relevant? If so could you help to get it rebased so we can merge it?

[stevenh]

It is still relevant, but I wouldn't recommend applying until you remove support for python 3.9, which is end of life in October.

Do you have a supported versions policy?