wasmer run coolreader18/rustpython-test


A Python-3 (CPython >= 3.9.0) Interpreter written in Rust 🐍 😱 🀘.

Build Status codecov License: MIT Contributors Gitter dependency status WAPM package Open in Gitpod


Check out our online demo running on WebAssembly.

RustPython requires Rust latest stable version (e.g 1.43.0 at May 24th 2020). To check Rust version: rustc --version If you wish to update, rustup update stable.

To build RustPython locally, do the following:

$ git clone
$ cd RustPython
  # --release is needed (at least on windows) to prevent stack overflow
$ cargo run --release
Hello, RustPython!

Or use the interactive shell:

$ cargo run --release
Welcome to rustpython
>>>>> 2+2

NOTE: For windows users, please set RUSTPYTHONPATH environment variable as Lib path in project directory. (e.g. When RustPython directory is C:\RustPython, set RUSTPYTHONPATH as C:\RustPython\Lib)

You can also install and run RustPython with the following:

$ cargo install --git
$ rustpython
Welcome to the magnificent Rust Python interpreter

(The rustpython-* crates are currently yanked from due to being out of date and not building on newer rust versions; we hope to release a new version Soonβ„’)

If you'd like to make https requests, you can enable the ssl feature, which also lets you install the pip package manager. Note that on Windows, you may need to install OpenSSL, or you can enable the ssl-vendor feature instead, which compiles OpenSSL for you but requires a C compiler, perl, and make.

Once you've installed rustpython with SSL support, you can install pip by running:

$ rustpython --install-pip

You can also install RustPython through the conda package manager, though this isn't officially supported and may be out of date:

$ conda install rustpython -c conda-forge
$ rustpython


You can compile RustPython to a standalone WebAssembly WASI module so it can run anywhere.

$ wapm install rustpython
$ wapm run rustpython
>>>>> 2+2

Building the WASI file

You can build the WebAssembly WASI file with:

cargo build --release --target wasm32-wasi --features="freeze-stdlib"

Note: we use the freeze-stdlib to include the standard library inside the binary. You also have to run once rustup target add wasm32-wasi.

JIT (Just in time) compiler

RustPython has an very experimental JIT compiler that compile python functions into native code.


By default the JIT compiler isn't enabled, it's enabled with the jit cargo feature.

$ cargo run --features jit

This requires autoconf, automake, libtool, and clang to be installed.


To compile a function, call __jit__() on it.

def foo():
    a = 5
    return 10 + a

foo.__jit__()  # this will compile foo to native code and subsequent calls will execute that native code
assert foo() == 15

Embedding RustPython into your Rust Applications

Interested in exposing Python scripting in an application written in Rust, perhaps to allow quickly tweaking logic where Rust's compile times would be inhibitive? Then examples/ and examples/ may be of some assistance.


RustPython is in development, and while the interpreter certainly can be used in interesting use cases like running Python in WASM and embedding into a Rust project, do note that RustPython is not totally production-ready.

Contribution is more than welcome! See our contribution section for more information on this.

Conference videos

Checkout those talks on conferences:

Use cases

Although RustPython is a fairly young project, a few people have used it to make cool projects:


  • Full Python-3 environment entirely in Rust (not CPython bindings)
  • A clean implementation without compatibility hacks


Currently along with other areas of the project, documentation is still in an early phase.

You can read the online documentation for the latest release, or the user guide.

You can also generate documentation locally by running:

$ cargo doc # Including documentation for all dependencies
$ cargo doc --no-deps --all # Excluding all dependencies

Documentation HTML files can then be found in the target/doc directory.


Contributions are more than welcome, and in many cases we are happy to guide contributors through PRs or on gitter. Please refer to the development guide as well for tips on developments.

With that in mind, please note this project is maintained by volunteers, some of the best ways to get started are below:

Most tasks are listed in the issue tracker. Check issues labeled with good first issue if you wish to start coding.

To enhance CPython compatibility, try to increase unittest coverage by checking this article: How to contribute to RustPython by CPython unittest

Another approach is to checkout the source code: builtin functions and object methods are often the simplest and easiest way to contribute.

You can also simply run ./ to assist in finding any unimplemented method.

Compiling to WebAssembly

See this doc


Chat with us on gitter.

Code of conduct

Our code of conduct can be found here.


The initial work was based on windelbouwman/rspython and shinglyu/RustPython


These are some useful links to related projects:


This project is licensed under the MIT license. Please see the LICENSE file for more details.

The project logo is licensed under the CC-BY-4.0 license. Please see the LICENSE-logo file for more details.

A Python-3 (CPython >= 3.5.0) Interpreter written in Rust 🐍 😱 🀘