https://github.com/synw/usepython
Run Python scripts in a Pyodide service worker
https://github.com/synw/usepython
Last synced: about 2 months ago
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Run Python scripts in a Pyodide service worker
- Host: GitHub
- URL: https://github.com/synw/usepython
- Owner: synw
- License: mit
- Created: 2022-08-25T09:11:25.000Z (almost 3 years ago)
- Default Branch: main
- Last Pushed: 2025-02-27T12:53:17.000Z (3 months ago)
- Last Synced: 2025-04-14T19:07:53.873Z (about 2 months ago)
- Language: TypeScript
- Size: 53.7 KB
- Stars: 9
- Watchers: 2
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# Use Python
[](https://www.npmjs.com/package/usepython)
A Python scripts runner composable. Run Python scripts in a [Pyodide](https://github.com/pyodide/pyodide) service worker
[Api doc](https://github.com/synw/usepython/tree/main/doc)
## Install
### As a package
```bash
npm install usepython
```
Then use it:
```ts
import { usePython } from "usepython";
const py = usePython();
```
### As script src
```html
const py = $py.usePython();
```
### As script type module
```html
import { usePython } from "https://unpkg.com/[email protected]/dist/py.esm.js";
const py = usePython();
```
## Usage
### Load the runtime
Load the Python runtime:
```ts
await py.load()
```
Listen to the install log:
```ts
const unbindInstallLog = py.installLog.listen((val) => {
console.log(`Installing Python, stage ${val.stage}: ${val.msg}`)
})
await py.load();
unbindInstallLog();
```
The install log object is a [nanostore](https://github.com/nanostores/nanostores#maps)
### Load libraries
It is possible to install some Python packages: either [packages built for Pyodide](https://pyodide.org/en/stable/usage/packages-in-pyodide.html#packages-in-pyodide), standard pip packages that will be installed with Micropip, or custom wheels
```ts
const wheel = '/acustomwheel-0.0.1-py3-none-any.whl';
const pyodideLibs = ['pandas', 'numpy', 'bokeh'];
await py.load(pyodideLibs, ['altair', wheel, 'vega_datasets'])
```
### Run Python code
Run some sync Python code:
```ts
const script = `a=1
b=2
a+b`
const { result, error } = await py.run(script);
```
The result is the last line of the script, just like a return value
See the [documentation](doc/modules.md)
To run async code use the `runAsync` function.
#### Namespaces
An optionnal namespace parameter can be used to isolate Python contexts:
```ts
const { result, error } = await py.run("a=1", "ns1");
```
The variable defined in the script will be accessible only in the
same namespace:
```ts
const { result, error } = await py.run("b=a+1", "ns1");
```
To flush the context of the namespace and reset all user defined
variables use the `clear` function:
```ts
await py.clear("ns1");
```
### Listen to stdout
Listen to the Python stdout output:
```ts
py.log.listen((val) => {
console.log("LOG", val.stdOut)
// val.stdErr is also available
});
const script = `print('ok from python')`;
await py.run(script);
```
The log object is a [nanostore](https://github.com/nanostores/nanostores#maps)
### State
[Atom stores](https://github.com/nanostores/nanostores#atoms) are available to listen to
the ready state and execution state of Python. Example:
```ts
py.isReady.listen((v) => console.log("Ready state:", v));
py.isExecuting.listen((v) => console.log("Execution state:", v));
```
Vuejs example:
```ts
import { useStore } from '@nanostores/vue';
const isExecuting: Readonly> = useStore(py.isExecuting);
const isReady: Readonly> = useStore(py.isReady);
```
## Examples
- [Script src](examples/umd/)
- [Script module](examples/esm/)
- [Vuejs](examples/vuejs/)
[Api doc](https://github.com/synw/usepython/tree/main/doc)