QCoreApplication::exec: The event loop is already running?

S

Sasha Tsikhun2021-01-05 22:07:37

Python

Sasha Tsikhun, 2021-01-05 22:07:37

As planned, this window should open first:

and then this (when you click on the second button):

But it opens the other way around
Here is the code:

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

# Form implementation generated from reading ui file 'main.ui'
#
# Created by: PyQt5 UI code generator 5.15.2
#
# WARNING: Any manual changes made to this file will be lost when pyuic5 is
# run again.  Do not edit this file unless you know what you are doing.


from PyQt5 import QtCore, QtGui, QtWidgets
# from mainApp import MainApp

class Ui_MainWindow(object):

    def open_per(self):
        # from mainApp import MainApp

        # self.window = QtWidgets.QMainWindow()
        self.ui = MainApp()

        # self.ui.setupUi(self.window)
        # self.window.show()

    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(500, 400)
        MainWindow.setStyleSheet("background-color:white")
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")
        self.label = QtWidgets.QLabel(self.centralwidget)
        self.label.setGeometry(QtCore.QRect(0, 20, 501, 41))
        self.label.setObjectName("label")
        self.pb1 = QtWidgets.QPushButton(self.centralwidget)
        self.pb1.setGeometry(QtCore.QRect(40, 110, 101, 21))
        self.pb1.setStyleSheet("color: #4B657A;")
        self.pb1.setObjectName("pb1")
        self.pb2 = QtWidgets.QPushButton(self.centralwidget)
        self.pb2.setGeometry(QtCore.QRect(40, 180, 101, 21))
        self.pb2.setStyleSheet("color: rgb(75, 101, 122);")
        self.pb2.setObjectName("pb2")
        # if self.pb2.clicked:
        self.pb2.clicked.connect(self.open_per)
        self.pb3 = QtWidgets.QPushButton(self.centralwidget)
        self.pb3.setGeometry(QtCore.QRect(40, 250, 101, 21))
        self.pb3.setStyleSheet("color: rgb(75, 101, 122);")
        self.pb3.setObjectName("pb3")
        self.pb4 = QtWidgets.QPushButton(self.centralwidget)
        self.pb4.setGeometry(QtCore.QRect(40, 310, 101, 21))
        self.pb4.setStyleSheet("color: #4B657A;")
        self.pb4.setObjectName("pb4")
        self.label_2 = QtWidgets.QLabel(self.centralwidget)
        self.label_2.setGeometry(QtCore.QRect(150, 70, 321, 301))
        self.label_2.setText("")
        self.label_2.setTextFormat(QtCore.Qt.AutoText)
        self.label_2.setPixmap(QtGui.QPixmap("2znak.png"))
        self.label_2.setScaledContents(True)
        self.label_2.setObjectName("label_2")
        MainWindow.setCentralWidget(self.centralwidget)
        self.statusbar = QtWidgets.QStatusBar(MainWindow)
        self.statusbar.setObjectName("statusbar")
        MainWindow.setStatusBar(self.statusbar)

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

    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
        self.label.setText(_translate("MainWindow", "<html><head/><body><p align=\"center\"><span style=\" font-size:14pt; font-weight:600; color: #4B657A;\">База даних мешканців студентського гуртожитка</span></p></body></html>"))
        self.pb1.setToolTip(_translate("MainWindow", "<html><head/><body><p align=\"center\">Реєстрація</p></body></html>"))
        self.pb1.setText(_translate("MainWindow", "Реєстрація"))
        self.pb2.setText(_translate("MainWindow", "Перегляд"))
        self.pb3.setText(_translate("MainWindow", "Довідка"))
        self.pb4.setText(_translate("MainWindow", "Про автора"))


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

I can make everything open normally, then 2 windows open:

And yet, how to make it impossible to enter an empty field or spaces in the input field?