Python-сообщество

 from login_forma import *
import sys
app = QtWidgets.QApplication(sys.argv)
MainWindow = QtWidgets.QMainWindow()
ui = Ui_MainWindow()
ui.setupUi(MainWindow)
application = Ui_MainWindow()
MainWindow.show() 
login = ui.Login_Edit.text()
def on_cliced():
    print (login)
ui.pushButton.clicked.connect(on_cliced)     
sys.exit(app.exec()) 

 from PyQt5 import QtCore, QtGui, QtWidgets
class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(800, 381)
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")
        self.pushButton = QtWidgets.QPushButton(self.centralwidget)
        self.pushButton.setGeometry(QtCore.QRect(250, 190, 75, 23))
        self.pushButton.setObjectName("pushButton")
        self.Login_Edit = QtWidgets.QLineEdit(self.centralwidget)
        self.Login_Edit.setGeometry(QtCore.QRect(200, 100, 113, 20))
        self.Login_Edit.setObjectName("Login_Edit")
        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.pushButton.setText(_translate("MainWindow", "PushButton"))
        self.Login_Edit.setText(_translate("MainWindow", "vvvvvv"))