如何删除迭代创建的 QLabels？

Question

I'm making an app where I'm iteratively creating QLabel . I'm trying to remove them with another button.

I want to remove the 'history'. I have tried different things like label.remove() and so on, but it would add no value to add my previous attempts here (also my attempts weren't on this reproducible example).

Here's the code that I have:

from PyQt5.QtWidgets import *
import sys

class MainWindow(QMainWindow):

    def __init__(self, *args, **kwargs):
        super(MainWindow, self).__init__(*args, **kwargs)
        self.left = 10
        self.top = 10
        self.width = 400
        self.height = 75
        self.initUI()

        self.layout = QVBoxLayout()

        self.line = QLineEdit()
        label = QLabel('Enter a WORD:')

        run_button = QPushButton('Run')
        reset_button = QPushButton('Reset History')

        self.layout.addWidget(label)
        self.layout.addWidget(self.line)
        self.layout.addWidget(run_button)
        self.layout.addWidget(reset_button)

        widget = QWidget()
        widget.setLayout(self.layout)

        run_button.clicked.connect(self.on_click)

        self.setCentralWidget(widget)

    def initUI(self):
        self.setGeometry(self.left, self.top, self.width, self.height)

    def on_click(self):
        response = QLabel(self.line.text())

        self.layout.addWidget(response)
        self.line.selectAll()


app = QApplication(sys.argv)

window = MainWindow()
window.show()

app.exec_()

Answer 1

You have to store the QLabels to later remove them from the layout and delete them, and then additionally recalculate the size of the window:

class MainWindow(QMainWindow):
    def __init__(self, *args, **kwargs):
        super(MainWindow, self).__init__(*args, **kwargs)
        self.left = 10
        self.top = 10
        self.width = 400
        self.height = 75
        self.initUI()

        self.layout = QVBoxLayout()

        self.line = QLineEdit()
        label = QLabel("Enter a WORD:")

        run_button = QPushButton("Run")
        reset_button = QPushButton("Reset History")

        self.layout.addWidget(label)
        self.layout.addWidget(self.line)
        self.layout.addWidget(run_button)
        self.layout.addWidget(reset_button)

        widget = QWidget()
        widget.setLayout(self.layout)

        run_button.clicked.connect(self.add_history)
        reset_button.clicked.connect(self.delete_history)

        self.setCentralWidget(widget)

        self._history_labels = []

    def initUI(self):
        self.setGeometry(self.left, self.top, self.width, self.height)

    def add_history(self):
        history = QLabel(self.line.text())
        self.layout.addWidget(history)
        self.line.selectAll()

        self._history_labels.append(history)

    def delete_history(self):
        for history in self._history_labels:
            self.layout.removeWidget(history)
            history.deleteLater()
        self._history_labels = []
        width = self.size().width()
        self.adjustSize()
        height = self.sizeHint().height()
        QTimer.singleShot(0, lambda: self.resize(width, height))

Answer 2

To me, it would be easier to use one label to store all of your responses. Every time you hit "Run" button, append a new line to your label. Changed lines highlighted with # <---

from PyQt5.QtWidgets import *
import sys

class MainWindow(QMainWindow):

    def __init__(self, *args, **kwargs):
        super(MainWindow, self).__init__(*args, **kwargs)
        self.left = 10
        self.top = 10
        self.width = 400
        self.height = 75
        self.initUI()

        self.layout = QVBoxLayout()

        self.line = QLineEdit()
        label = QLabel('Enter a WORD:')

        run_button = QPushButton('Run')
        reset_button = QPushButton('Reset History')
        
        self.label = QLabel()               # <-----

        self.layout.addWidget(label)
        self.layout.addWidget(self.line)
        self.layout.addWidget(run_button)
        self.layout.addWidget(reset_button)
        self.layout.addWidget(self.label)   # <-----

        widget = QWidget()
        widget.setLayout(self.layout)

        run_button.clicked.connect(self.on_click)
        reset_button.clicked.connect(self.reset_click) # <-----

        self.setCentralWidget(widget)

    def initUI(self):
        self.setGeometry(self.left, self.top, self.width, self.height)

    def on_click(self):
        self.label.setText(self.label.text() + '\n' + self.line.text())  # <-----

        self.line.selectAll()

    def reset_click(self):       # <-----
        self.label.setText('')   # <-----

app = QApplication(sys.argv)

window = MainWindow()
window.show()

app.exec_()

        self.layout = QVBoxLayout()

        self.line = QLineEdit()
        label = QLabel('Enter a WORD:')

        run_button = QPushButton('Run')
        reset_button = QPushButton('Reset History')
        
        self.label = QLabel()               # <-----

        self.layout.addWidget(label)
        self.layout.addWidget(self.line)
        self.layout.addWidget(run_button)
        self.layout.addWidget(reset_button)
        self.layout.addWidget(self.label)   # <-----

        widget = QWidget()
        widget.setLayout(self.layout)

        run_button.clicked.connect(self.on_click)
        reset_button.clicked.connect(self.reset_click) # <-----

        self.setCentralWidget(widget)

    def initUI(self):
        self.setGeometry(self.left, self.top, self.width, self.height)

    def on_click(self):
        self.label.setText(self.label.text() + '\n' + self.line.text()) # <-----

        self.line.selectAll()

    def reset_click(self):        # <-----
        self.label.setText('')    # <-----

app = QApplication(sys.argv)

window = MainWindow()
window.show()

app.exec_()