Qt Framework, PyQt5 and AttributeError: ‘MyApp’ object has no attribute ‘myAttribute’

Last week I started to learn Python and I developed some command line apps. Now I would like to develop apps with GUI. I searched in internet and I found a project that fits my needs: Qt Project (http://qt-project.org) and PyQt (http://www.riverbankcomputing.com/software/pyqt/intro). I installed Qt 5.3.2 Open Source, SIP 4.16.4, PyQt5 5.3.2 on Mac OS X 10.10 and python 2.7.6. After some troubles on installing Qt and PyQt, finally I managed to make them work. If I open example projects from PyQt example folder the gui appears without any problems. So I created my GUI with Qt Creator and then I used pyuic5 to generate python code. This is what pyuic5 created (file name “myapp_auto.py“):

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

# Form implementation generated from reading ui file '/Users/andrea/Developer/Qt/mainwindow.ui'
#
# Created: Mon Nov 17 14:20:14 2014
#      by: PyQt5 UI code generator 5.3.2
#
# 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(400, 300)
        self.centralWidget = QtWidgets.QWidget(MainWindow)
        self.centralWidget.setObjectName("centralWidget")
        self.ok = QtWidgets.QPushButton(self.centralWidget)
        self.ok.setGeometry(QtCore.QRect(140, 120, 115, 32))
        self.ok.setAccessibleName("")
        self.ok.setObjectName("ok")
        self.text = QtWidgets.QLabel(self.centralWidget)
        self.text.setGeometry(QtCore.QRect(100, 70, 181, 16))
        self.text.setAccessibleName("")
        self.text.setAlignment(QtCore.Qt.AlignCenter)
        self.text.setObjectName("text")
        self.time = QtWidgets.QDateTimeEdit(self.centralWidget)
        self.time.setGeometry(QtCore.QRect(100, 180, 194, 24))
        self.time.setAccessibleName("")
        self.time.setObjectName("time")
        MainWindow.setCentralWidget(self.centralWidget)
        self.menuBar = QtWidgets.QMenuBar(MainWindow)
        self.menuBar.setGeometry(QtCore.QRect(0, 0, 400, 22))
        self.menuBar.setObjectName("menuBar")
        self.menuMyApp = QtWidgets.QMenu(self.menuBar)
        self.menuMyApp.setObjectName("menuMyApp")
        self.menuEdit = QtWidgets.QMenu(self.menuBar)
        self.menuEdit.setObjectName("menuEdit")
        MainWindow.setMenuBar(self.menuBar)
        self.mainToolBar = QtWidgets.QToolBar(MainWindow)
        self.mainToolBar.setObjectName("mainToolBar")
        MainWindow.addToolBar(QtCore.Qt.TopToolBarArea, self.mainToolBar)
        self.statusBar = QtWidgets.QStatusBar(MainWindow)
        self.statusBar.setObjectName("statusBar")
        MainWindow.setStatusBar(self.statusBar)
        self.menuBar.addAction(self.menuMyApp.menuAction())
        self.menuBar.addAction(self.menuEdit.menuAction())

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

    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
        self.ok.setText(_translate("MainWindow", "Ok"))
        self.text.setText(_translate("MainWindow", "I'm a GUI"))
        self.menuMyApp.setTitle(_translate("MainWindow", "MyApp"))
        self.menuEdit.setTitle(_translate("MainWindow", "Edit"))

After that I added a new python file where I put my code; this is what i wrote (file name “myapp.py“):

#!/usr/bin/env python

from PyQt5.QtCore import *
from PyQt5.QtWidgets import *
from PyQt5.QtGui import *
from myapp_auto import Ui_MainWindow
import sys
import time


class MyApp(Ui_MainWindow):

    parse_triggered = pyqtSignal()

    def __init__(self, parent=None, name=None):
        Ui_MainWindow.__init__(self)

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

Then, I run myapp.py and I verified that all GUI elements appeared to be where they should be. Well…now arrive my issue: I tried to access with code the “time” element in MainWindow modifying init def thus:

def __init__(self, parent=None, name=None):
            Ui_MainWindow.__init__(self)

            # Set the date to now
            now = QDateTime()
            now.setTime_t(int(time.time()))
            self.time.setDateTime(now)

But the compiler shows alway this error:

AttributeError: ‘MyApp’ object has no attribute ‘time’

This happen even if I try to access any other element (“ok”, “text”). Will surely be a stupid mistake but I just can not figure out where I went wrong. Thank you all guys! Have a good day,

Andrea

Answer

You’re not far off.

The MyApp class needs to inherit QMainWindow, and you don’t need to use the time module. Try something like this:

class MyApp(QMainWindow, Ui_MainWindow):
    parse_triggered = pyqtSignal()

    def __init__(self, parent=None, name=None):
        super(MyApp, self).__init__(parent)
        self.setupUi(self)
        # Set the date to now
        self.time.setDateTime(QDateTime.currentDateTime())

if __name__ == "__main__":

    app = QApplication(sys.argv)
    window = MyApp()
    window.show()
    sys.exit(app.exec_())