I'm trying to make the text in a QLabel change according to what the user selects in a combobox, the text I want to set being the __repr__ function of the class. Here's the code I'm using to try to do what I want to:

class MainWindow(QMainWindow):
    def __init__(self):
        super().__init__()

        self.setWindowTitle("Resonant Orbit Calculator")
        self.setMinimumSize(QSize(500, 400))

        m_label = QLabel()
        m_label.setText(object)

        c_box = QComboBox()
        c_box.addItems(planet.name for planet in planets_objects)
        c_box.addItems(moon.name for moon in moons_objects)

        c_box.currentTextChanged.connect(self.text_changed)

        layout = QVBoxLayout()
        layout.addWidget(m_label)
        layout.addWidget(c_box)

        widget = QWidget()
        widget.setLayout(layout)

        self.setCentralWidget(widget)

    def text_changed(self, t):
        for element in planets_objects   moons_objects:
            if element.name == t:
                object = element
                break
        print(object)

        return object

And the error I'm getting is TypeError: setText(self, str): argument 1 has unexpected type 'type'. I kind of get that I'm using the wrong kind of information to set the QLabel as, but I can't figure out how else to do it.

CodePudding user response：

There are few mistakes.

1. object is special object/class in Python and you shouldn't use it as variable.

2. you use setText(object) in __init__ but you never assign text to variable object

3. you should use self. in self.m_label to have access to this widget in other functions.

4. in other functions you have to use setText(..) to change text in label. You can't change it by assigning new text to variable object

If you need result from __repr__ then use repr(...)

class MainWindow(QMainWindow):
    def __init__(self):
        super().__init__()

        self.setWindowTitle("Resonant Orbit Calculator")
        self.setMinimumSize(QSize(500, 400))

        self.m_label = QLabel()
        self.m_label.setText('Default text on start')

        c_box = QComboBox()
        c_box.addItems(planet.name for planet in planets_objects)
        c_box.addItems(moon.name for moon in moons_objects)

        c_box.currentTextChanged.connect(self.text_changed)

        layout = QVBoxLayout()
        layout.addWidget(m_label)
        layout.addWidget(c_box)

        widget = QWidget()
        widget.setLayout(layout)

        self.setCentralWidget(widget)

    def text_changed(self, selected):
        for element in planets_objects   moons_objects:
            if element.name == selected:
                #self.m_label.setText(element)
                self.m_label.setText(repr(element))
                break
                # OR
                #return

BTW: text_changed is executed by PyQt but it doesn't know what to do with returned value - so using return object is useless.