PyQt5--QFontDiaglog

 # -*- coding:utf-8 -*-
 '''
 Created on Sep 17, 2018

 @author: SaShuangYiBing

 Comment:
 '''
 import sys
 from PyQt5.QtWidgets import QApplication,QWidget,QFontDialog,QLabel,QVBoxLayout,QPushButton,QSizePolicy

 class New_test(QWidget):
     def __init__(self):
         super().__init__()
         self.initUI()

     def initUI(self):
         vbox = QVBoxLayout()

         btn = QPushButton('Diaglog',self)
         btn.setSizePolicy(QSizePolicy.Fixed,QSizePolicy.Fixed)
         btn.move(20,20)
         btn.clicked.connect(self.showdiaglog)

         self.lbl = QLabel('Knowledge only matters',self)
         self.lbl.move(150,20)

         vbox.addWidget(btn)
         vbox.addWidget(self.lbl)
         self.setLayout(vbox)

         self.setGeometry(300,300,250,180)
         self.setWindowTitle('Font Diaglog')
         self.show()

     def showdiaglog(self):
         font,ok = QFontDialog.getFont()
         if ok:
             self.lbl.setFont(font)

 if __name__ == '__main__':
     app = QApplication(sys.argv)
     ex = New_test()
     sys.exit(app.exec_())