feat: port over initial python schema extraction PoC

[mistermoe]

Summary

This PR ports python schema extraction PoC into this repo

Warning

Still mostly unusable but this lays in the vast majority of a foundation.

Changes

• refactor verb decorator. switched to using a pattern that doesn't require dynamic dangling mutable properties on functions. Instead encapsulates decorated verb functions in a class and extracts type information useful for runtime grpc server and schema extraction
• sets up initial stab at a directory structure. will attempt to create 1 package per schema feature. each package will contain:
  • encapsulating class
  • decorator
  • schema extraction
• minor refactor of VerbExtractor to use isinstance(func, Verb) instead of getattr(func, "_is_ftl_verb", False).
• set up runnable schema_extractor (note: this will change in the next PR to a standalone executable. temporarily in a cli dir)
• added TODO in python language plugin's Build method

props to @worstell for doing the actual schema extraction work! will co-author the merge commit

Usage

Note

From the python-runtime/ftl dir

❯ uv run python -m ftl.cli.schema_extractor $(pwd)/../../examples/python/echo
Error importing module decorator: attempted relative import with no known parent package
/Users/moe/code/tbd/ose/ftl/python-runtime/ftl/src/ftl/extract/context.py:76: UserWarning: google.protobuf.service module is deprecated. RPC implementations should provide code generator plugins which generate code specific to the RPC implementation. service.py will be removed in Jan 2025
  spec.loader.exec_module(module)
Extracted Decl:
pos {
  filename: "/path/to/ftl/python-runtime/ftl/../../examples/python/echo/echo.py"
  line: 17
}
name: "echo"
request {
  ref {
    name: "EchoRequest"
    module: "echo"
  }
}
response {
  ref {
    name: "EchoResponse"
    module: "echo"
  }
}

Extracted Decl:
pos {
  filename: "/path/to/ftl/python-runtime/ftl/../../examples/python/echo/echo.py"
  line: 7
}
name: "EchoRequest"
fields {
  name: "name"
  type {
    string {
    }
  }
}

Extracted Decl:
pos {
  filename: "/path/to/ftl/python-runtime/ftl/../../examples/python/echo/echo.py"
  line: 12
}
name: "EchoResponse"
fields {
  name: "message"
  type {
    string {
    }
  }
}

[alecthomas]

This doesn't seem necessary? No source links on the project page either.

Python bindings to the Google search engine.

[mistermoe]

nope good catch. artifact from poc. removed it

[alecthomas]

Missing annotations here and elsewhere?

I'd like it if all the Python code were fully typed, and linted for typing too?

[mistermoe]

yep agreed! just configured the linter to require type annotations for everything: e8b9bf2

will go through and annotate everything now

[alecthomas]

Do these other functions need to be exported?

[alecthomas]

Maybe these should be _private?

[alecthomas]

Not sure what state this is in, so maybe this is a bit premature, but using __module__ isn't going to be sufficient IIRC?

[mistermoe]

aye chatted with @worstell , probably not going to be sufficient. will leave this to tackle in a subsequent PR