[FIXED] PYQT5: How to link the 3 pushbottons with 3 .py

Issue

How to use pyqtSlot to connect the QMainWindow with 3 QtWidgets?

I wanna to use 3 buttons to switch 3 screen for each .py files.

The UiPE.py file for the 3 pushbutton to switch 3 screens of .py file.

#=============
**UiPE.py**
#=============    
# -*- coding: utf-8 -*-

"""
Module implementing PB01.
"""

from PyQt5.QtCore import pyqtSlot
from PyQt5.QtWidgets import QMainWindow

from Ui_UiPE import Ui_MainWindow


class PB01(QMainWindow, Ui_MainWindow):
    """
    Class documentation goes here.
    """
    def __init__(self, parent=None):
        """
        Constructor

        @param parent reference to the parent widget
        @type QWidget
        """
        super(PB01, self).__init__(parent)
        self.setupUi(self)

    @pyqtSlot()
    def on_PBtn1PE_clicked(self):
    """
    Slot documentation goes here.
    """
    # TODO: not implemented yet
    #raise NotImplementedError

@pyqtSlot()
def on_PBtn2LC_clicked(self):
    """
    Slot documentation goes here.
    """
    # TODO: not implemented yet
    raise NotImplementedError

@pyqtSlot()
def on_PBtn3PP_clicked(self):
    """
    Slot documentation goes here.
    """
    # TODO: not implemented yet
    raise NotImplementedError


if __name__ == "__main__":
    import sys
    app = QtWidgets.QApplication(sys.argv)
    FormPE = QtWidgets.QWidget()
    ui = Ui_FormPE()
    ui.setupUi(FormPE)
    FormPE.show()
    sys.exit(app.exec_())

Ui_UiPE.py

#=============
**Ui_UiPE.py**
#=============
# -*- coding: utf-8 -*-

/*Form implementation generated from reading ui file
 '..\PyQt5\eee\UiPE.ui'*/
#
# Created by: PyQt5 UI code generator 5.11.3
#
# 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(960, 736)
        self.centralWidget = QtWidgets.QWidget(MainWindow)
        self.centralWidget.setStyleSheet("border-image:\ 
        url(:/ME/images/Main.jpg);")

        self.centralWidget.setObjectName("centralWidget")
        self.frame = QtWidgets.QFrame(self.centralWidget)
        self.frame.setGeometry(QtCore.QRect(0, 0, 960, 500))
        self.frame.setAutoFillBackground(False)
        self.frame.setFrameShape(QtWidgets.QFrame.StyledPanel)
        self.frame.setFrameShadow(QtWidgets.QFrame.Raised)
        self.frame.setObjectName("frame")
        self.PBtn1PE = QtWidgets.QPushButton(self.frame)
        self.PBtn1PE.setEnabled(True)
        self.PBtn1PE.setGeometry(QtCore.QRect(150, 400, 150, 50))
        font = QtGui.QFont()
        font.setFamily("MingLi")
        font.setPointSize(18)
        font.setBold(False)
        font.setWeight(50)
        self.PBtn1PE.setFont(font)
        self.PBtn1PE.setStyleSheet("border:2px groove gray;\
        border-radius:10px;padding:2px 4px;background-color: \
        red;border-image: url();")

        self.PBtn1PE.setText("PE")
        self.PBtn1PE.setDefault(False)
        self.PBtn1PE.setObjectName("PBtn1PE")

        self.PBtn2LC = QtWidgets.QPushButton(self.frame)
        self.PBtn2LC.setGeometry(QtCore.QRect(400, 400, 150, 50))
        font = QtGui.QFont()
        font.setFamily("MingLi")
        font.setPointSize(18)
        font.setBold(False)
        font.setWeight(50)
        self.PBtn2LC.setFont(font)
        self.PBtn2LC.setStyleSheet("border:2px groove gray;\
        border-radius:10px;padding:2px 4px;background-color: \
        yellow;border-image: url();")

        self.PBtn2LC.setObjectName("PBtn2LC")

        self.PBtn3PP = QtWidgets.QPushButton(self.frame)
        self.PBtn3PP.setGeometry(QtCore.QRect(650, 400, 150, 50))
        font = QtGui.QFont()
        font.setFamily("MingLi")
        font.setPointSize(18)
        font.setBold(False)
        font.setWeight(50)
        self.PBtn3PP.setFont(font)
        self.PBtn3PP.setAutoFillBackground(False)
        self.PBtn3PP.setStyleSheet("border:2px groove gray;\
        border-radius:10px;padding:2px 4px;background-color: \
        rgb(0, 162, 232);;border-image: url();")

        self.PBtn3PP.setObjectName("PBtn3PP")

        self.BtnClose = QtWidgets.QPushButton(self.frame)
        self.BtnClose.setGeometry(QtCore.QRect(860, 40, 81, 41))
        font = QtGui.QFont()
        font.setFamily("MingLi")
        font.setPointSize(16)
        font.setBold(True)
        font.setWeight(75)
        self.BtnClose.setFont(font)
        self.BtnClose.setWhatsThis("")
        self.BtnClose.setAccessibleName("")
        self.BtnClose.setAutoFillBackground(False)
        self.BtnClose.setStyleSheet("border:2px groove gray;\
        border-radius:10px;padding:2px 4px;background-color: red;\
        border-image: url();")

        self.BtnClose.setText("Exit")
        self.BtnClose.setObjectName("BtnClose")

        MainWindow.setCentralWidget(self.centralWidget)

        self.retranslateUi(MainWindow)
        self.PBtn1PE.released.connect(MainWindow.show)
        self.BtnClose.clicked.connect(self.frame.close)
        QtCore.QMetaObject.connectSlotsByName(MainWindow)
        MainWindow.setTabOrder(self.PBtn1PE, self.PBtn2LC)
        MainWindow.setTabOrder(self.PBtn2LC, self.PBtn3PP)

    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
        self.PBtn2LC.setText(_translate("MainWindow", "LC"))
        self.PBtn3PP.setText(_translate("MainWindow", "PP"))

#import MainE_rc

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

Ui_UiPE1.py

/*=============
#**Ui_UiPE1.py**, **Ui_UiLC.py** and **Ui_UiPP.py** is same script for 
#differet function.
=============*/
# -*- coding: utf-8 -*-

# Form implementation generated from reading ui file \
#'C:\Users\ST3C_01\PyQt5\eee\UiPE1.ui'
#
# Created by: PyQt5 UI code generator 5.11.3
#
# WARNING! All changes made in this file will be lost!

from PyQt5 import QtCore, QtGui, QtWidgets

class Ui_FormPE(object):
    def setupUi(self, FormPE):
        FormPE.setObjectName("FormPE")
        FormPE.resize(960, 500)
        font = QtGui.QFont()
        font.setFamily("MingLi")
        font.setPointSize(16)
        FormPE.setFont(font)
        FormPE.setStyleSheet("border-image:\ 
        url(:/myframe/images/PresidentElection.jpg);")

        self.PEBtn1B = QtWidgets.QPushButton(FormPE)
        self.PEBtn1B.setGeometry(QtCore.QRect(540, 420, 111, 40))
        self.PEBtn1B.setMaximumSize(QtCore.QSize(120, 40))
        font = QtGui.QFont()
        font.setFamily("MingLi")
        font.setPointSize(18)
        font.setBold(True)
        font.setWeight(75)
        self.PEBtn1B.setFont(font)
        self.PEBtn1B.setLayoutDirection(QtCore.Qt.RightToLeft)
        self.PEBtn1B.setText("  Decrease")
        self.PEBtn1B.setObjectName("PEBtn1B")

        self.PEBtn1A = QtWidgets.QPushButton(FormPE)
        self.PEBtn1A.setGeometry(QtCore.QRect(550, 30, 111, 40))
        self.PEBtn1A.setMaximumSize(QtCore.QSize(120, 40))
        font = QtGui.QFont()
        font.setFamily("MingLi")
        font.setPointSize(18)
        font.setBold(True)
        font.setWeight(75)
        self.PEBtn1A.setFont(font)
        self.PEBtn1A.setLayoutDirection(QtCore.Qt.RightToLeft)
        self.PEBtn1A.setText("  Increase")
        self.PEBtn1A.setObjectName("PEBtn1A")

        self.PEBtn2A = QtWidgets.QPushButton(FormPE)
        self.PEBtn2A.setGeometry(QtCore.QRect(690, 30, 111, 40))
        self.PEBtn2A.setMaximumSize(QtCore.QSize(120, 40))
        font = QtGui.QFont()
        font.setFamily("MingLi")
        font.setPointSize(18)
        font.setBold(True)
        font.setWeight(75)
        self.PEBtn2A.setFont(font)
        self.PEBtn2A.setLayoutDirection(QtCore.Qt.RightToLeft)
        self.PEBtn2A.setText("  Increase")
        self.PEBtn2A.setObjectName("PEBtn2A")

        self.PEBtn3A = QtWidgets.QPushButton(FormPE)
        self.PEBtn3A.setGeometry(QtCore.QRect(830, 30, 111, 40))
        self.PEBtn3A.setMaximumSize(QtCore.QSize(120, 40))
        font = QtGui.QFont()
        font.setFamily("MingLi")
        font.setPointSize(18)
        font.setBold(True)
        font.setWeight(75)
        self.PEBtn3A.setFont(font)
        self.PEBtn3A.setLayoutDirection(QtCore.Qt.RightToLeft)
        self.PEBtn3A.setText("  Increase")
        self.PEBtn3A.setObjectName("PEBtn3A")

        self.PEBtn2B = QtWidgets.QPushButton(FormPE)
        self.PEBtn2B.setGeometry(QtCore.QRect(690, 420, 111, 40))
        self.PEBtn2B.setMaximumSize(QtCore.QSize(120, 40))
        font = QtGui.QFont()
        font.setFamily("MingLi")
        font.setPointSize(18)
        font.setBold(True)
        font.setWeight(75)
        self.PEBtn2B.setFont(font)
        self.PEBtn2B.setLayoutDirection(QtCore.Qt.RightToLeft)
        self.PEBtn2B.setText("  Decrease")
        self.PEBtn2B.setObjectName("PEBtn2B")

        self.PEBtn3B = QtWidgets.QPushButton(FormPE)
        self.PEBtn3B.setGeometry(QtCore.QRect(830, 420, 111, 40))
        self.PEBtn3B.setMaximumSize(QtCore.QSize(120, 40))
        font = QtGui.QFont()
        font.setFamily("MingLi")
        font.setPointSize(18)
        font.setBold(True)
        font.setWeight(75)
        self.PEBtn3B.setFont(font)
        self.PEBtn3B.setLayoutDirection(QtCore.Qt.RightToLeft)
        self.PEBtn3B.setText("  Decrease")
        self.PEBtn3B.setObjectName("PEBtn3B")

        self.retranslateUi(FormPE)
        QtCore.QMetaObject.connectSlotsByName(FormPE)

    def retranslateUi(self, FormPE):
        _translate = QtCore.QCoreApplication.translate
        FormPE.setWindowTitle(_translate("FormPE", "Form"))

#import PE_rc

if __name__ == "__main__":
    import sys
    app = QtWidgets.QApplication(sys.argv)
    FormPE = QtWidgets.QWidget()
    ui = Ui_FormPE()
    ui.setupUi(FormPE)
    FormPE.show()
    sys.exit(app.exec_())

The above is my example.

Solution

Try it:

import sys
from PyQt5 import QtCore, QtGui, QtWidgets
from PyQt5.QtCore import pyqtSlot
from PyQt5.QtWidgets import QMainWindow

class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
#        MainWindow.resize(960, 536)
        MainWindow.setFixedSize(960, 470)                                                 # +
        self.centralWidget = QtWidgets.QWidget(MainWindow)
#        self.centralWidget.setStyleSheet("border-image: url(Ok.png);")
        self.centralWidget.setObjectName("centralWidget")                                 # +++
        self.centralWidget.setStyleSheet("#centralWidget {border-image: url(Ok.png);}")   # +++

        self.frame = QtWidgets.QFrame(self.centralWidget)
        self.frame.setGeometry(QtCore.QRect(0, 0, 960, 500))
        self.frame.setAutoFillBackground(False)
        self.frame.setFrameShape(QtWidgets.QFrame.StyledPanel)
        self.frame.setFrameShadow(QtWidgets.QFrame.Raised)
        self.frame.setObjectName("frame")

        self.PBtn1PE = QtWidgets.QPushButton(self.frame)
        self.PBtn1PE.setEnabled(True)
        self.PBtn1PE.setGeometry(QtCore.QRect(150, 400, 150, 50))
        font = QtGui.QFont()
        font.setFamily("MingLi")
        font.setPointSize(18)
        font.setBold(False)
        font.setWeight(50)
        self.PBtn1PE.setFont(font)
        self.PBtn1PE.setStyleSheet("""
            border: 2px groove gray;
            border-radius: 10px; 
            padding: 2px 4px;
            background-color: red;
        """)
        self.PBtn1PE.setText("PE")
        self.PBtn1PE.setDefault(False)
        self.PBtn1PE.setObjectName("PBtn1PE")

        self.PBtn2LC = QtWidgets.QPushButton(self.frame)
        self.PBtn2LC.setGeometry(QtCore.QRect(400, 400, 150, 50))
        font = QtGui.QFont()
        font.setFamily("MingLi")
        font.setPointSize(18)
        font.setBold(False)
        font.setWeight(50)
        self.PBtn2LC.setFont(font)
        self.PBtn2LC.setStyleSheet("border:2px groove gray;\
        border-radius:10px;padding:2px 4px;background-color: yellow;")
        self.PBtn2LC.setObjectName("PBtn2LC")

        self.PBtn3PP = QtWidgets.QPushButton(self.frame)
        self.PBtn3PP.setGeometry(QtCore.QRect(650, 400, 150, 50))
        font = QtGui.QFont()
        font.setFamily("MingLi")
        font.setPointSize(18)
        font.setBold(False)
        font.setWeight(50)
        self.PBtn3PP.setFont(font)
        self.PBtn3PP.setAutoFillBackground(False)
        self.PBtn3PP.setStyleSheet("border:2px groove gray;\
        border-radius:10px;padding:2px 4px;background-color: rgb(0, 162, 232);")
        self.PBtn3PP.setObjectName("PBtn3PP")

        self.BtnClose = QtWidgets.QPushButton(self.frame)
        self.BtnClose.setGeometry(QtCore.QRect(860, 40, 81, 41))
        font = QtGui.QFont()
        font.setFamily("MingLi")
        font.setPointSize(16)
        font.setBold(True)
        font.setWeight(75)
        self.BtnClose.setFont(font)
        self.BtnClose.setWhatsThis("")
        self.BtnClose.setAccessibleName("")
        self.BtnClose.setAutoFillBackground(False)
        self.BtnClose.setStyleSheet("border:2px groove gray;\
        border-radius:10px;padding:2px 4px;background-color: red;")
        self.BtnClose.setText("Exit")
        self.BtnClose.setObjectName("BtnClose")

        MainWindow.setCentralWidget(self.centralWidget)

        self.retranslateUi(MainWindow)
        self.PBtn1PE.released.connect(MainWindow.show)
        self.BtnClose.clicked.connect(self.frame.close)
        QtCore.QMetaObject.connectSlotsByName(MainWindow)

        MainWindow.setTabOrder(self.PBtn1PE, self.PBtn2LC)
        MainWindow.setTabOrder(self.PBtn2LC, self.PBtn3PP)

    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
        self.PBtn2LC.setText(_translate("MainWindow", "LC"))
        self.PBtn3PP.setText(_translate("MainWindow", "PP"))


class Ui_FormPE(object):
    def setupUi(self, FormPE):
        FormPE.setObjectName("FormPE")
        FormPE.resize(960, 500)
        font = QtGui.QFont()
        font.setFamily("MingLi")
        font.setPointSize(16)
        FormPE.setFont(font)
        FormPE.setStyleSheet("#FormPE {border-image: url(im.png);}")   # + #FormPE

        self.PEBtn1B = QtWidgets.QPushButton(FormPE)
        self.PEBtn1B.setGeometry(QtCore.QRect(540, 420, 111, 40))
        self.PEBtn1B.setMaximumSize(QtCore.QSize(120, 40))
        font = QtGui.QFont()
        font.setFamily("MingLi")
        font.setPointSize(16)                                          # 16
        font.setBold(True)
        font.setWeight(75)
        self.PEBtn1B.setFont(font)
        self.PEBtn1B.setLayoutDirection(QtCore.Qt.RightToLeft)
        self.PEBtn1B.setText(" Decrease ")                             # " Decrease "
        self.PEBtn1B.setObjectName("PEBtn1B")

        self.PEBtn1A = QtWidgets.QPushButton(FormPE)
        self.PEBtn1A.setGeometry(QtCore.QRect(550, 30, 111, 40))
        self.PEBtn1A.setMaximumSize(QtCore.QSize(120, 40))
        font = QtGui.QFont()
        font.setFamily("MingLi")
        font.setPointSize(16)
        font.setBold(True)
        font.setWeight(75)
        self.PEBtn1A.setFont(font)
        self.PEBtn1A.setLayoutDirection(QtCore.Qt.RightToLeft)
        self.PEBtn1A.setText(" Increase ")
        self.PEBtn1A.setObjectName("PEBtn1A")

        self.PEBtn2A = QtWidgets.QPushButton(FormPE)
        self.PEBtn2A.setGeometry(QtCore.QRect(690, 30, 111, 40))
        self.PEBtn2A.setMaximumSize(QtCore.QSize(120, 40))
        font = QtGui.QFont()
        font.setFamily("MingLi")
        font.setPointSize(16)
        font.setBold(True)
        font.setWeight(75)
        self.PEBtn2A.setFont(font)
        self.PEBtn2A.setLayoutDirection(QtCore.Qt.RightToLeft)
        self.PEBtn2A.setText(" Increase ")
        self.PEBtn2A.setObjectName("PEBtn2A")

        self.PEBtn3A = QtWidgets.QPushButton(FormPE)
        self.PEBtn3A.setGeometry(QtCore.QRect(830, 30, 111, 40))
        self.PEBtn3A.setMaximumSize(QtCore.QSize(120, 40))
        font = QtGui.QFont()
        font.setFamily("MingLi")
        font.setPointSize(16)
        font.setBold(True)
        font.setWeight(75)
        self.PEBtn3A.setFont(font)
        self.PEBtn3A.setLayoutDirection(QtCore.Qt.RightToLeft)
        self.PEBtn3A.setText(" Increase ")
        self.PEBtn3A.setObjectName("PEBtn3A")

        self.PEBtn2B = QtWidgets.QPushButton(FormPE)
        self.PEBtn2B.setGeometry(QtCore.QRect(690, 420, 111, 40))
        self.PEBtn2B.setMaximumSize(QtCore.QSize(120, 40))
        font = QtGui.QFont()
        font.setFamily("MingLi")
        font.setPointSize(16)
        font.setBold(True)
        font.setWeight(75)
        self.PEBtn2B.setFont(font)
        self.PEBtn2B.setLayoutDirection(QtCore.Qt.RightToLeft)
        self.PEBtn2B.setText(" Decrease ")
        self.PEBtn2B.setObjectName("PEBtn2B")

        self.PEBtn3B = QtWidgets.QPushButton(FormPE)
        self.PEBtn3B.setGeometry(QtCore.QRect(830, 420, 111, 40))
        self.PEBtn3B.setMaximumSize(QtCore.QSize(120, 40))
        font = QtGui.QFont()
        font.setFamily("MingLi")
        font.setPointSize(16)
        font.setBold(True)
        font.setWeight(75)
        self.PEBtn3B.setFont(font)
        self.PEBtn3B.setLayoutDirection(QtCore.Qt.RightToLeft)
        self.PEBtn3B.setText(" Decrease ")
        self.PEBtn3B.setObjectName("PEBtn3B")

        self.retranslateUi(FormPE)
        QtCore.QMetaObject.connectSlotsByName(FormPE)

    def retranslateUi(self, FormPE):
        _translate = QtCore.QCoreApplication.translate
        FormPE.setWindowTitle(_translate("FormPE", "Form"))


class PB01(QMainWindow, Ui_MainWindow):
    def __init__(self, parent=None):
        super(PB01, self).__init__(parent)

        self.setupUi(self)

    @pyqtSlot()
    def on_PBtn1PE_clicked(self):
        print("on_PBtn1PE_clicked")

        self.FormPE = QtWidgets.QWidget()
        ui = Ui_FormPE()
        ui.setupUi(self.FormPE)
        self.FormPE.show()

    @pyqtSlot()
    def on_PBtn2LC_clicked(self):
        print("on_PBtn2LC_clicked")

    @pyqtSlot()
    def on_PBtn3PP_clicked(self):
        print("on_PBtn3PP_clicked")


if __name__ == "__main__":
    import sys
    app = QtWidgets.QApplication(sys.argv)

    w = PB01()                                                # +++
    w.show()                                                  # +++

#    FormPE = QtWidgets.QWidget()
#    ui = Ui_FormPE()
#    ui.setupUi(FormPE)
#    FormPE.show()

    sys.exit(app.exec_())

Answered By - S. Nick