qtrio 0.4.0

a library bringing Qt GUIs together with ``async`` and ``await`` via Trio

Resources

Documentation	Read the Docs
Chat	Gitter
Forum	Discourse
Issues	GitHub
Repository	GitHub
Tests	GitHub Actions
Coverage	Codecov
Distribution	PyPI

Introduction

Note:

This library is in early development. It works. It has tests. It has documentation. Expect breaking changes as we explore a clean API. By paying this price you get the privilege to provide feedback via GitHub issues to help shape our future. :]

The QTrio project’s goal is to bring the friendly concurrency of Trio using Python’s async and await syntax together with the GUI features of Qt to enable more correct code and a more pleasant developer experience. QTrio is permissively licensed to avoid introducing restrictions beyond those of the underlying Python Qt library you choose. Both PySide2 and PyQt5 are supported.

By enabling use of async and await it is possible in some cases to write related code more concisely and clearly than you would get with the signal and slot mechanisms of Qt concurrency. See the README examples in the docs for the full code. The first example here shows classic pure Qt code.

class Main:
    def __init__(
        self,
        input_dialog: typing.Optional[QtWidgets.QInputDialog] = None,
        output_dialog: typing.Optional[QtWidgets.QMessageBox] = None,
    ):
        if input_dialog is None:  # pragma: nocover
            input_dialog = create_input()

        if output_dialog is None:  # pragma: nocover
            output_dialog = create_output()

        self.input_dialog = input_dialog
        self.output_dialog = output_dialog

    def setup(self) -> None:
        self.input_dialog.accepted.connect(self.input_accepted)
        self.input_dialog.rejected.connect(self.input_rejected)

        self.input_dialog.show()

    def input_accepted(self) -> None:
        name = self.input_dialog.textValue()

        self.output_dialog.setText(f"Hi {name}, welcome to the team!")

        self.output_dialog.finished.connect(self.output_finished)
        self.output_dialog.show()

    def input_rejected(self) -> None:
        QtCore.QCoreApplication.instance().quit()

    def output_finished(self) -> None:
        QtCore.QCoreApplication.instance().quit()

The second example, below, shows how using async and await allows for a more concise and clear description of the sequenced activity.

async def main(
    input_dialog: typing.Optional[qtrio.dialogs.TextInputDialog] = None,
    output_dialog: typing.Optional[qtrio.dialogs.MessageBox] = None,
) -> None:
    if input_dialog is None:  # pragma: nocover
        input_dialog = create_input()

    if output_dialog is None:  # pragma: nocover
        output_dialog = create_output()

    with contextlib.suppress(qtrio.UserCancelledError):
        name = await input_dialog.wait()

        output_dialog.text = f"Hi {name}, welcome to the team!"

        await output_dialog.wait()