How to align a QPushButton inside window?

Question

I want to align a QPushButton to the bottom right corner, but without a fixed size, because if I use a fixed size and resize the window, it doen't look good anymore. Here's my code:

    self.copy_btn = QtWidgets.QPushButton(self)
    self.copy_btn.setText("Copy")
    self.copy_btn.move(370, 350)

As you can see, I'm currenctly using .move(). I tried it with .setAlignment(QtCore.Qt.AlignRight), because it worked for the label, but it doesn't work for QPushButton.

Answer 1

There are several solutions depending on the context:

• Using a QXBoxLayout

  from PyQt5 import QtCore, QtWidgets
  
  
  class Widget(QtWidgets.QWidget):
      def __init__(self, parent=None):
          super().__init__(parent)
  
          self.copy_btn = QtWidgets.QPushButton()
          self.copy_btn.setText("Copy")
  
          lay = QtWidgets.QVBoxLayout(self)
          lay.setContentsMargins(0, 0, 0, 0)
          lay.addStretch()
          lay.addWidget(self.copy_btn, alignment=QtCore.Qt.AlignRight)
  
          # or
          # lay = QtWidgets.QHBoxLayout(self)
          # lay.setContentsMargins(0, 0, 0, 0)
          # lay.addStretch()
          # lay.addWidget(self.copy_btn, alignment=QtCore.Qt.AlignBottom)
  
          self.resize(640, 480)
  
  
  if __name__ == "__main__":
      import sys
  
      app = QtWidgets.QApplication(sys.argv)
  
      w = Widget()
      w.show()
  
      sys.exit(app.exec_())
  

• Using an eventFilter

  from PyQt5 import QtCore, QtWidgets
  
  
  class Resizer(QtCore.QObject):
      def __init__(self, widget):
          super().__init__(widget)
  
          self._widget = widget
  
          self.widget.installEventFilter(self)
          if not self.widget.isWindow():
              self.widget.window().installEventFilter(self)
  
      @property
      def widget(self):
          return self._widget
  
      def eventFilter(self, obj, event):
          if obj is self.widget and not self.widget.isWindow():
              if event.type() == QtCore.QEvent.ParentAboutToChange:
                  self.widget.window().removeEventFilter(self)
              elif event.type() == QtCore.QEvent.ParentChange:
                  self.widget.window().installEventFilter(self)
  
          if obj is self.widget.window() and event.type() == QtCore.QEvent.Resize:
              geom = self.widget.geometry()
              geom.moveBottomRight(QtCore.QPoint(event.size().width(), event.size().height()))
              self.widget.setGeometry(geom)
          return super().eventFilter(obj, event)
  
  
  class Widget(QtWidgets.QWidget):
      def __init__(self, parent=None):
          super().__init__(parent)
  
          self.copy_btn = QtWidgets.QPushButton(self)
          self.copy_btn.setText("Copy")
  
          resizer = Resizer(self.copy_btn)
          self.resize(640, 480)
  
  
  if __name__ == "__main__":
      import sys
  
      app = QtWidgets.QApplication(sys.argv)
  
      w = Widget()
      w.show()
  
      sys.exit(app.exec_())