decpys 0.1.0

A Qt library extension for building declarative programming -style UIs completely within python.

Declarative PySide6

decpys (or Dec-larative PyS-ide) is a Python library that acts as a thin wrapper around the original PySide6 to enable super-fast GUI prototyping using modern declarative UI techniques completely within Python. decpys is licensed under GPLv2.

Installation

decpys is available through PyPI. From the command-line, simply:

pip install decpys

Design

decpys is inspired by UI frameworks like React and Flutter. decpys extends the popular PySide6 Qt library so that Qt widgets can be used in a intuitive, concise manner to build out declarative-style UI blocks completely within python.

Normally, Qt is used to build UIs in an imperative manner. This means that each widget and its properties must be set, step-by-step. This might look familiar to you:

window = QMainWindow()
widget = QWidget()
label = QLabel()
label.setText("a label")
layout = QVBoxLayout()
layout.addWidget(label)
widget.setLayout(layout)
window.setCentralWidget(widget)
window.setWindowTitle("a window")

It's cumbersome. Qt introduced QML a while back, but that introduces a new syntax and file format to learn. Tools also have to be made in IDEs/editors to give users the speed they seek developing.

Let's take a look at the last example, this time written using decpys:

window = qMainWindow(
    title="a window",
    centralWidget=qWidget(
        layout=qVBoxLayout(
            children=[
                qLabel(
                    text="a label"
                )
            ]
        )
    )
)

Indents lend themselves well to visualizing widget hierarchy. Python's keyword arguments (and many IDEs' support for type hinting) help the user find relevant properties. If you've ever used a declarative-UI framework, you know the benefits it brings to productivity and readable code.

See the ClickableButton example for a more involved look at how decpys can be used.