QML module not found when using qmlRegisterType()

duyjuwumu

I'm following the QML 6 Book examples for Qt for Python. I'm following the last example using psutil but Qt Creator says QML module not found when I use qmlRegisterType to expose a Python class to QML. How can I fix this?

Note: the code runs as expected, but I can't switch to QtQuickDesigner in Qt Creator to modify the QML. This is the main reason I want to use Qt Creator, so getting this working is important to me. Can anyone help? Below is the code:

// main.py
# This Python file uses the following encoding: utf-8
import psutil
import sys

from PySide2.QtGui import QGuiApplication
from PySide2.QtQml import QQmlApplicationEngine, qmlRegisterType
from PySide2.QtCore import Qt, QUrl, QTimer, QAbstractListModel

class CpuLoadModel(QAbstractListModel):
    def __init__(self):
        QAbstractListModel.__init__(self)

        self.__cpu_count = psutil.cpu_count()
        self.__cpu_load = [0] * self.__cpu_count

        self.__update_timer = QTimer(self)
        self.__update_timer.setInterval(1000)
        self.__update_timer.timeout.connect(self.__update)
        self.__update_timer.start()

        # The first call returns invalid data
        psutil.cpu_percent(percpu=True)

    def __update(self):
        self.__cpu_load = psutil.cpu_percent(percpu=True)
        self.dataChanged.emit(self.index(0,0), self.index(self.__cpu_count-1, 0))

    def rowCount(self, parent):
        return self.__cpu_count

    def data(self, index, role):
        if (role == Qt.DisplayRole and
            index.row() >= 0 and
            index.row() < len(self.__cpu_load) and
            index.column() == 0):
            return self.__cpu_load[index.row()]
        else:
            return None

if __name__ == '__main__':
    app = QGuiApplication(sys.argv)
    engine = QQmlApplicationEngine()

    qmlRegisterType(CpuLoadModel, 'PsUtils', 1, 0, 'CpuLoadModel')  # this is how i'm exposing the model to QML

    engine.load(QUrl("main.qml"))

    if not engine.rootObjects():
        sys.exit(-1)

    sys.exit(app.exec_())

// main.qml
import QtQuick 2.15
import QtQuick.Window 2.15

import PsUtils 1.0 // this is what's causing the error

Window {
    id: root

    width: 640
    height: 480
    visible: true
    title: qsTr("CPU Load")

    ListView {
        anchors.fill: parent
        model: CpuLoadModel { }
        delegate: Rectangle {
            id: delegate

            required property int display

            width: parent.width
            height: 30
            color: "white"

            Rectangle {
                id: bar
                width: parent.width * delegate.display / 100.0
                height: 30
                color: "green"
            }

            Text {
                anchors.verticalCenter: parent.verticalCenter
                x: Math.min(bar.x + bar.width + 5, parent.width-width)
                text: delegate.display + "%"
            }
        }
    }
}

I'm on Ubuntu 18.04 with the following environment

$ python
Python 3.9.4 (default, Apr  9 2021, 01:15:05) 
[GCC 5.4.0 20160609] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import PySide2
>>> PySide2.__version__
'5.15.2'

Qt Creator info

Qt Creator 4.15.0
Based on Qt 5.15.2 (GCC 7.3.1 20180303 (Red Hat 7.3.1-5), 64 bit)

Built on May 4 2021 01:17:20

From revision 978f6caf1e