Pyqt5 how to set pushbutton click event to obtain file address

PyQt5 How to set up PushButton Click the event to get the file address

One 、 design sketch

Click on that to have 3 A little button

Two 、 Realization

Core code ：
stay def setupUi(self, MainWindow): Add... To the last line self.toolButton.clicked.connect(self.msg)
Then add a member function msg that will do

    ################button Button click event callback function ################
    self.toolButton.clicked.connect(self.msg)

def msg(self, Filepath):
    m = QtWidgets.QFileDialog.getExistingDirectory(None, " Select a folder ", "C:/")  #  Starting path 
    self.lineEdit_3.setText(m)

3、 ... and 、 Test code

notes ： You may not open ui, Because there is no picture

# -*- coding: utf-8 -*-

# Form implementation generated from reading ui file 'ImgGenerate.ui'
#
# Created by: PyQt5 UI code generator 5.9.2
#
# WARNING! All changes made in this file will be lost!

from PyQt5 import QtCore, QtGui, QtWidgets

class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(500, 300)
        sizePolicy = QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.Fixed, QtWidgets.QSizePolicy.Fixed)
        sizePolicy.setHorizontalStretch(0)
        sizePolicy.setVerticalStretch(0)
        sizePolicy.setHeightForWidth(MainWindow.sizePolicy().hasHeightForWidth())
        MainWindow.setSizePolicy(sizePolicy)
        MainWindow.setMinimumSize(QtCore.QSize(500, 300))
        MainWindow.setMaximumSize(QtCore.QSize(500, 300))
        icon = QtGui.QIcon()

 

        icon.addPixmap(QtGui.QPixmap("logo.ico"), QtGui.QIcon.Normal, QtGui.QIcon.Off)
      

        MainWindow.setWindowIcon(icon)
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")
        self.label_4 = QtWidgets.QLabel(self.centralwidget)
        self.label_4.setGeometry(QtCore.QRect(0, 0, 491, 271))
        sizePolicy = QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.Fixed, QtWidgets.QSizePolicy.Fixed)
        sizePolicy.setHorizontalStretch(0)
        sizePolicy.setVerticalStretch(0)
        sizePolicy.setHeightForWidth(self.label_4.sizePolicy().hasHeightForWidth())
        self.label_4.setSizePolicy(sizePolicy)
        self.label_4.setMinimumSize(QtCore.QSize(491, 271))
        self.label_4.setMaximumSize(QtCore.QSize(491, 271))
        self.label_4.setText("")

  
        self.label_4.setPixmap(QtGui.QPixmap("begin.jpg"))
       
        self.label_4.setObjectName("label_4")
        self.widget = QtWidgets.QWidget(self.centralwidget)
        self.widget.setGeometry(QtCore.QRect(70, 30, 372, 181))
        self.widget.setObjectName("widget")
        self.gridLayout = QtWidgets.QGridLayout(self.widget)
        self.gridLayout.setContentsMargins(0, 0, 0, 0)
        self.gridLayout.setObjectName("gridLayout")
        self.label_5 = QtWidgets.QLabel(self.widget)
        font = QtGui.QFont()
        font.setFamily(" Regular script ")
        font.setPointSize(14)
        self.label_5.setFont(font)
        self.label_5.setObjectName("label_5")
        self.gridLayout.addWidget(self.label_5, 0, 0, 1, 1)
        self.label = QtWidgets.QLabel(self.widget)
        font = QtGui.QFont()
        font.setFamily(" Regular script ")
        font.setPointSize(14)
        self.label.setFont(font)
        self.label.setObjectName("label")
        self.gridLayout.addWidget(self.label, 1, 0, 1, 1)
        self.label_2 = QtWidgets.QLabel(self.widget)
        font = QtGui.QFont()
        font.setFamily(" Regular script ")
        font.setPointSize(14)
        self.label_2.setFont(font)
        self.label_2.setObjectName("label_2")
        self.gridLayout.addWidget(self.label_2, 2, 0, 1, 1)
        self.label_3 = QtWidgets.QLabel(self.widget)
        font = QtGui.QFont()
        font.setFamily(" Regular script ")
        font.setPointSize(14)
        self.label_3.setFont(font)
        self.label_3.setObjectName("label_3")
        self.gridLayout.addWidget(self.label_3, 3, 0, 1, 1)
        self.lineEdit_3 = QtWidgets.QLineEdit(self.widget)
        self.lineEdit_3.setObjectName("lineEdit_3")
        self.gridLayout.addWidget(self.lineEdit_3, 3, 1, 1, 1)
        self.toolButton = QtWidgets.QToolButton(self.widget)
        self.toolButton.setObjectName("toolButton")
        self.gridLayout.addWidget(self.toolButton, 3, 2, 1, 1)
        self.pushButton = QtWidgets.QPushButton(self.widget)
        font = QtGui.QFont()
        font.setFamily("Arial")
        font.setPointSize(12)
        self.pushButton.setFont(font)
        self.pushButton.setIconSize(QtCore.QSize(20, 20))
        self.pushButton.setObjectName("pushButton")
        self.gridLayout.addWidget(self.pushButton, 4, 1, 1, 1)
        self.comboBox = QtWidgets.QComboBox(self.widget)
        self.comboBox.setObjectName("comboBox")
        self.comboBox.addItem("")
        self.comboBox.addItem("")
        self.gridLayout.addWidget(self.comboBox, 0, 1, 1, 1)
        self.lineEdit_2 = QtWidgets.QLineEdit(self.widget)
        font = QtGui.QFont()
        font.setFamily(" Regular script ")
        font.setPointSize(14)
        self.lineEdit_2.setFont(font)
        self.lineEdit_2.setObjectName("lineEdit_2")
        self.gridLayout.addWidget(self.lineEdit_2, 2, 1, 1, 1)
        self.lineEdit = QtWidgets.QLineEdit(self.widget)
        sizePolicy = QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.Fixed, QtWidgets.QSizePolicy.Fixed)
        sizePolicy.setHorizontalStretch(0)
        sizePolicy.setVerticalStretch(0)
        sizePolicy.setHeightForWidth(self.lineEdit.sizePolicy().hasHeightForWidth())
        self.lineEdit.setSizePolicy(sizePolicy)
        font = QtGui.QFont()
        font.setFamily(" Regular script ")
        font.setPointSize(14)
        self.lineEdit.setFont(font)
        self.lineEdit.setText("")
        self.lineEdit.setObjectName("lineEdit")
        self.gridLayout.addWidget(self.lineEdit, 1, 1, 1, 1)
        MainWindow.setCentralWidget(self.centralwidget)
        self.statusbar = QtWidgets.QStatusBar(MainWindow)
        self.statusbar.setObjectName("statusbar")
        MainWindow.setStatusBar(self.statusbar)
        self.menuBar = QtWidgets.QMenuBar(MainWindow)
        self.menuBar.setGeometry(QtCore.QRect(0, 0, 500, 23))
        self.menuBar.setObjectName("menuBar")
        self.menu = QtWidgets.QMenu(self.menuBar)
        self.menu.setObjectName("menu")
        self.menu_2 = QtWidgets.QMenu(self.menu)
        self.menu_2.setObjectName("menu_2")
        self.menu_3 = QtWidgets.QMenu(self.menu)
        self.menu_3.setObjectName("menu_3")
        MainWindow.setMenuBar(self.menuBar)
        self.action41 = QtWidgets.QAction(MainWindow)
        self.action41.setObjectName("action41")
        self.action4 = QtWidgets.QAction(MainWindow)
        self.action4.setObjectName("action4")
        self.action = QtWidgets.QAction(MainWindow)
        self.action.setObjectName("action")
        self.actionVison_1_4 = QtWidgets.QAction(MainWindow)
        self.actionVison_1_4.setObjectName("actionVison_1_4")
        self.action_4 = QtWidgets.QAction(MainWindow)
        self.action_4.setObjectName("action_4")
        self.menu_2.addAction(self.actionVison_1_4)
        self.menu_3.addAction(self.action_4)
        self.menu.addAction(self.menu_2.menuAction())
        self.menu.addAction(self.menu_3.menuAction())
        self.menuBar.addAction(self.menu.menuAction())

        self.retranslateUi(MainWindow)
        QtCore.QMetaObject.connectSlotsByName(MainWindow)
        ################button Button click event callback function ################
        self.toolButton.clicked.connect(self.msg)

    def msg(self, Filepath):
        m = QtWidgets.QFileDialog.getExistingDirectory(None, " Select a folder ", "C:/")  #  Starting path 
        self.lineEdit_3.setText(m)

    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", " Wind falling picture crawler "))
        self.label_5.setText(_translate("MainWindow", "  Crawl to the website ："))
        self.label.setText(_translate("MainWindow", " Image search words ："))
        self.label_2.setText(_translate("MainWindow", "  Crawling quantity ："))
        self.label_3.setText(_translate("MainWindow", "  Save address ："))
        self.toolButton.setText(_translate("MainWindow", "..."))
        self.pushButton.setText(_translate("MainWindow", " To start generating "))
        self.comboBox.setItemText(0, _translate("MainWindow", "bing"))
        self.comboBox.setItemText(1, _translate("MainWindow", "baidu"))
        self.menu.setTitle(_translate("MainWindow", " Related information "))
        self.menu_2.setTitle(_translate("MainWindow", " Version number "))
        self.menu_3.setTitle(_translate("MainWindow", " developer "))
        self.action41.setText(_translate("MainWindow", "41"))
        self.action4.setText(_translate("MainWindow", " Version number "))
        self.action.setText(_translate("MainWindow", " developer "))
        self.actionVison_1_4.setText(_translate("MainWindow", "Vison:2.4"))
        self.action_4.setText(_translate("MainWindow", " The wind blows the fallen leaves "))


from PyQt5.QtWidgets import QApplication,QMainWindow
import sys
if __name__=='__main__':
    app=QApplication(sys.argv)
    MainWindow=QMainWindow()
    ui=Ui_MainWindow()
    ui.setupUi(MainWindow)
    MainWindow.show()
    sys.exit((app.exec_()))