NPython

Python programming VM implemented in Nim.

Online playground demo ↓	Read API Docs
(by compiling Nim to Javascript)	Wiki about History

Purpose

• Fun and practice. Learn both Python and Nim.
• Serve as a altertive small version of CPython (as of 0.1.1, less than 2MB on release build mode)
• Used as plugin for those using WASM

How to use

Easiest installation

nimble install npython

Then you can use as if using python, e.g.

npython --version
npython -c "print('hello, NPython')"

Manually Install (e.g. JS backend)

Or you may wanna build for js backend or something else:

prepare

git clone https://github.com/nimpylib/npython.git
cd npython

NPython support C backend and multiply JS backends:

after build passing -h flag to npython and you will see help message

For a binary executable (C backend)

nimble build
bin/npython

For a WASM executable (wasi-sdk backend)

nimble buildWasm
wasmtime --invoke NimMain bin/npython.wasm

For JS backend

• NodeJS: nimble buildJs -d:nodejs
• Deno: nimble buildJs -d:deno
• Browser, prompt&alert-based repl: nimble buildJs -d:jsAlert
• single page website: nimble buildKarax (requires nimble install karax). This is how online playground runs

Status

Capable of:

• flow control with if else, while, for, ...
• function (closure) defination and call. Decorators.
• builtin print, dir, len, range, tuple, list, dict, exceptions, etc.
• import such as import foo.
• raise exceptions, basic try ... except XXXError ... , with detailed traceback message. Assert statement.
• interactive mode and file mode
• ...

Check out ./tests to see more examples.

Todo

• integrate with nimpylib
• builtin compat dict
• better bigint lib
• ... ref Todo on Wiki