每次变量更改时，第二个窗口中的PYQT5更新标签

from PyQt5.QtCore import pyqtSignal, QObject

class Variable(QObject):
    valueChanged = pyqtSignal(str)
    
    def __init__(self):
        super().__init__()
        self._value = ""
    
    @property
    def value(self):
        return self._value
    
    @value.setter
    def value(self, new_value):
        self._value = new_value
        self.valueChanged.emit(new_value)

from PyQt5.QtWidgets import QLabel, QVBoxLayout, QWidget
from PyQt5.QtCore import Qt

class SecondWindow(QWidget):
    def __init__(self, variable):
        super().__init__()
        self.variable = variable
        self.variable.valueChanged.connect(self.update_label)
        
        self.label = QLabel()
        layout = QVBoxLayout()
        layout.addWidget(self.label)
        self.setLayout(layout)
    
    def update_label(self, new_value):
        self.label.setText(new_value)