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#348: JavaScript in Your Python

Published Tue, Aug 15, 2023, recorded Tue, Aug 15, 2023
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Brian #1: Differentiating between writing down dependencies to use packages and for packages themselves

  • Brett Cannon
  • Why can’t we just use pyproject.toml and stop using requirements.txt?
  • Nope. At least not yet. They’re currently for different things.
  • pyproject.toml
    • There’s project.dependencies and project.optional-dependencies.tests that kinda would work for listing dependencies for an app.
    • But you can’t say pip install -r pyproject.toml. It doesn’t work. And that’s weird.
    • project is intended for packaged projects.
  • requirements.txt
    • for applications and other non-packaged projects
    • It has specific versions
    • works great with pip
  • What then?
    • Either we stick with requirements.txt
    • Or we invent some other file, maybe requirements.toml?
    • Or maybe (Brian’s comment), add something like [application] and application.dependencies and application.optional-dependencies.tests to pyproject.toml

Michael #2: PythonMonkey

  • PythonMonkey is a Mozilla SpiderMonkey JavaScript engine embedded into the Python VM, using the Python engine to provide the JS host environment.
  • This product is in an early stage, approximately 80% to MVP as of July 2023. It is under active development by Distributive. External contributions and feedback are welcome and encouraged.
  • It will enable JavaScript libraries to be used seamlessly in Python code and vice versa — without any significant performance penalties.
  • Call Python packages like NumPy from within a JavaScript library, or use NPM packages like [crypto-js]( directly from Python.
  • Executing WebAssembly modules in Python becomes trivial using the WebAssembly API and engine from SpiderMonkey.
  • More details in Will Pringle’s article.

Brian #3: Quirks of Python package versioning

  • Seth Larson
  • Yes, we have SemVer, 1.2.3, and CalVer, 2023.6.1, and suffixes for pre-release, 1.2.3pre1.
  • But it gets way more fun than that, if you get creative
  • Here’s a few
    • v is an optional prefix, like v.1.0
    • You can include an “Epoch” and separate it from the version with a !, like 20!1.2.3
    • Local versions with alphanumerics, periods, dashes, underscores, like 1.0.0+ubuntu-1. PyPI rejects those. That’s probably good.
    • Long versions. There’s no max length for a version number. How about
    • Pre, post, dev aren’t mutually exclusive: 1.0.0-pre0-post0-dev0
    • More craziness in article
  • -

Michael #4: bear-type

  • Beartype is an open-source PEP-compliant near-real-time pure-Python runtime type-checker emphasizing efficiency, usability, and thrilling puns.
  • Annotate @beartype-decorated classes and callables with type hints.

    • Call those callables with valid parameters: Transparent
    • Call those callables with invalid parameters: Boom

    Traceback: raise exception_cls( beartype.roar.BeartypeCallHintParamViolation: @beartyped quote_wiggum() parameter lines=[b'Oh, my God! A horrible plane crash!', b'Hey, everybody! Get a load of thi...'] violates type hint list[str], as list item 0 value b'Oh, my God! A horrible plane crash!' not str.




Joke: Learning JavaScript

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