QHBoxLayout 中最小宽度的 QPushButton?

QPushButton of minimal width in QHBoxLayout?

我想创建带有文本 "X" 的 QPushButton 以关闭 window。我想把它放在按钮的栏上。为此,我制作了 QHLayout。

layTop=QHBoxLayout()

self.btnMenu=QPushButton("Menu") #just as sample of button with normal size
layTop.addWidget(self.btnMenu)

btnX=QPushButton("X")  #I need it small
btnX.setSizePolicy(QSizePolicy.Minimum,QSizePolicy.Preferred) #I try this, but it's not work as I expected
layTop.addWidget(btnX)

但是,"X" 按钮和其他按钮一样大。如何让它变窄?

(此代码的屏幕截图如下)

使用 QToolButton 代替 QPushButton: