目标:
通过Python调用PyQt5的相关库函数，实现自定义槽函数并调用

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
Created on Tue Feb 27 15:37:50 2018

@author: liuqiang
"""


from PyQt5.QtWidgets import QApplication, QWidget, QPushButton
from PyQt5.QtCore import pyqtSlot
 
class App(QWidget):
 
    def __init__(self):
        super(App, self).__init__()
        self.title = 'PyQt5 button'
        self.left = 10
        self.top = 10
        self.width = 640
        self.height = 480
        self.initUI()
 
    def initUI(self):
        self.setWindowTitle(self.title)
        self.setGeometry(self.left, self.top, self.width, self.height)
 
        button = QPushButton('PyQt5 button', self)
        button.setToolTip('This is an example button')
        button.move(100,70) 
        button.clicked.connect(self.on_click)
 
        self.show()
 
    @pyqtSlot()
    def on_click(self):
        print('PyQt5 button click')
 
if __name__ == '__main__':
    import sys
    app = QApplication(sys.argv)
    ex = App()
    sys.exit(app.exec_())

运行结果为：

Screenshot from 2018-02-27 16-13-55.png