pymiro

Signal-native, declarative GUI framework for Python.

What is pymiro?

pymiro is a modern GUI framework for Python that brings web-like declarative syntax and fine-grained reactivity to the desktop. Inspired by SolidJS, it uses a signal-based reactivity engine and a keyed virtual DOM to efficiently update Qt widgets (PySide6) without relying on heavy class hierarchies or complex event bindings.

Why pymiro?

Feature	tkinter	PyQt6 / PySide6	pymiro
Declarative	❌	❌	✅
Reactive signals	❌	❌	✅
Component model	❌	❌	✅
Hot reload	❌	❌	✅
Theming	❌	manual	✅
Type safe	❌	partial	✅

Installation

pip install pymiro

Requires Python 3.12+

Quick start

import sys
from PySide6.QtWidgets import QApplication
from pymiro.core import signal, component, effect
from pymiro.elements import Window, VBox, Text, Button
from pymiro.renderer import render

@component
def Counter():
    count, set_count = signal(0)
    
    return Window(title="pymiro Counter")(
        VBox()(
            Text(text=lambda: f"Count: {count()}"),
            Button(text="Increment", on_click=lambda: set_count(count() + 1)),
            Button(text="Decrement", on_click=lambda: set_count(count() - 1))
        )
    )

if __name__ == "__main__":
    app = QApplication(sys.argv)
    render(Counter(), None)
    sys.exit(app.exec())

Core concepts

Signals

Signals are the primitives of reactivity in pymiro. They track state and automatically update any components or effects that depend on them.

from pymiro.core import signal, computed

count, set_count = signal(5)
double_count = computed(lambda: count() * 2)

print(double_count()) # 10
set_count(10)
print(double_count()) # 20

Components

Components in pymiro are simple functions decorated with @component that return virtual nodes representing the UI.

from pymiro.core import component
from pymiro.elements import VBox, Text

@component
def Greeting(name: str):
    return VBox()(
        Text(text=f"Hello, {name}!")
    )

Theming

pymiro includes a built-in design token system and light/dark themes that can be applied to your application easily.

from pymiro.theme import ThemeProvider, DarkTheme
from pymiro.elements import Window

@component
def App():
    return ThemeProvider(theme=DarkTheme())(
        Window()(
            # Your components here...
        )
    )

Project status

Alpha — API may change before 1.0.0. Check out our Roadmap.

Contributing

See CONTRIBUTING.md for details on how to set up the project and run tests.

License

MIT