A Python Interpreter Written in Python

blueybingo 5 minutes ago | parent | next [-]

the article glosses over something worth pausing on: the `getattr` trick for dispatching instructions (replacing the big if-elif chain) is actaully a really elegant pattern that shows up in a lot of real interpreters and command dispatchers, not just toy ones -- worth studying that bit specifically if you're building anything with extensible command sets.

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anitil 3 hours ago | parent | prev | next [-]

Oooh it's a bytecode interpreter! I was wondering how they'd fit a parser/tokenizer in 500 lines unless the first was `import tokenizer, parser`. And it looks like 1500ish lines according to tokei

I think because python is a stack-based interpreter this is a really great way to get some exposure to how it works if you're not too familiar with C. A nice project!

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tekknolagi 3 hours ago | parent | prev | next [-]

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bjoli 3 hours ago | parent [-]

And, in some ways, PyPy. I still think it is the sanest way to implement Python.

It makes me sad that I have to write C to make any meaningful changes to Python. Same goes for ruby. Rubinius was such a nice project.

Hacking on schemes and lisps made me realize how much more fun it is when the language is implemented in the language itself. It also makes sure you have the right abstractions for solving a bunch of real problems.

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anitil 3 hours ago | parent [-]

> And, in some ways, PyPy

What do you mean by that? I'm not familiar with PyPy

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nxpnsv 3 hours ago | parent [-]

PyPy is python implemented in python. It is fast.

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notpushkin 2 hours ago | parent | next [-]

https://pypy.org/

It lags behind CPython in features and currently only supports Python versions up to 3.11. There was a big discussion a month ago: https://news.ycombinator.com/item?id=47293415

But you can help! https://pypy.org/howtohelp.html

https://opencollective.com/pypy

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Doxin 2 hours ago | parent | prev [-]

PyPy is python implemented in RPython, which is technically a python subset. It's so restricted it might as well be a different language though.

	▲	bjoli 30 minutes ago \| parent [-]
		It is restricted in a way that you would restrict yourself to write high speed software in most languages, and I found it is not that restrictive compared to C that you would have to use if you were to write a fast Python library.

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woadwarrior01 an hour ago | parent | prev | next [-]

aka A Metacircular Interpreter

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hcfman 2 hours ago | parent | prev [-]

Just wondering why you stopped there? Why not a python interpreter for a python interpreter for python ?

	▲	dnnddidiej 24 minutes ago \| parent [-]
		It already is that.