main.py

import sys
from PyQt5.QtWidgets import (QLineEdit, QVBoxLayout, QMainWindow,
    QWidget, QDesktopWidget, QApplication, QPushButton, QLabel,
    QComboBox, QFileDialog, QRadioButton)
from PyQt5.QtCore import pyqtSlot, QByteArray
from alert import Window2
from test import test

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

    def initUI(self):
        self.resize(300, 150)
        self.setWindowTitle('TEST')

        self.resultsGen = QPushButton('TEST', self)
        self.resultsGen.clicked.connect(lambda: self.on_click())

        self.show()

    @pyqtSlot()
    def on_click(self):
        test(self)

if __name__ == '__main__':
    app = QApplication(sys.argv)
    sg = SG()

    sys.exit(app.exec_())
======================================================================================================
alert.py

from PyQt5.QtWidgets import (QLineEdit, QVBoxLayout, QMainWindow,
    QWidget, QDesktopWidget, QApplication, QPushButton, QLabel,
    QComboBox, QFileDialog, QRadioButton)
from PyQt5.QtCore import pyqtSlot, QByteArray
from PyQt5.QtGui import QPixmap

from PyQt5 import QtGui, QtCore

class Window2(QMainWindow):
    def __init__(self):
        super().__init__()
        self.initPopup()

    def initPopup(self):
        self.resize(500, 500)
        self.setWindowTitle("Window22222")
        self.central_widget = QWidget()
        self.setCentralWidget(self.central_widget)
        lay = QVBoxLayout(self.central_widget)

        label = QLabel(self)
        pixmap = QPixmap('cropped/8.png')
        label.setPixmap(pixmap)
        self.resize(pixmap.width(), pixmap.height())

        lay.addWidget(label)

        self.textbox = QLineEdit(self)
        self.textbox.move(20, 20)
        self.textbox.resize(280, 40)

        # Create a button in the window
        self.button = QPushButton('Show text', self)
        self.button.move(20, 80)
        # connect button to function on_click
        self.button.clicked.connect(lambda: self.on_clickX())
        self.show()

    @pyqtSlot()
    def on_clickX(self):
        textboxValue = self.textbox.text()
        print(textboxValue)
        self.textbox.setText("")
        self.hide()

======================================================================================================
test.py

from alert import Window2

def test(self):
    for i in range(2):
        for x in range(6):
            w = Window2()