vs Pyodide

pymport vs PyScript/Pyodide

Although both projects provide similar functionality, they are completely unrelated with very different design goals:

• pymport goal is to allow using standard Python libraries without any modification in Node.js - it brings software such as numpy, pandas to Node.js
• Pyodide goal is to allow using Python code in a modified interpreter both in the browser and in Node.js - it allows scripting a web page in Python

Comparison:

Software	pymport	Pyodide
Target JS Environment	Node.js	Node.js & Browser
Compatibility	all existing Python libraries w/o modification	libraries ported to Pyodide
Contains binary platform-dependent code	requires binaries for the specific platform, supports Windows, Linux & macOS	fully portable
Python stdlib support	all	most
Existing external environment support	yes, but must compile C++	no
Special semantics for expressing all missing language features	yes	yes
Performance	native	3x to 5x slower
Interpreter support	Standard CPython, latest 3.12 version comes built-in	Modified recent CPython
Using Python objects from JS	yes, with a transparent Proxy	yes, with a transparent Proxy
Using JS objects from Python	not directly, must copy-convert with fromJS before calling Python	yes, with a transparent proxy type from the js module
Round-trip conversion of objects restores the original	only Python to JS to Python	both
Calling Python functions from JS	yes	yes
Calling JS functions from Python	yes	yes
Asynchronous calling from JS to Python	yes	no
Asynchronous calling from Python to JS	no	yes
Interoperability between JS Promise and Python Future	no	yes
Exception conversion	bi-directional	bi-directional
Program entrypoint	must be JavaScript	JavaScript or Python
Redirecting stdio	no	from Python to JavaScript
Inline Python in JavaScript	only eval context	full
Importing .py files	may load from the filesystem	may load from an URL
worker_threads	yes, all threads share a single Python interpreter	yes, each thread runs a separate Python interpreter
TypeScript support	partial, TypeScript typings for the project itself, but does not generate TypeScript typings for Python packages	partial, TypeScript typings for the project itself, but does not generate TypeScript typings for Python packages