Getting `Name Error:` in python code as shared below. I am a beginner in Python.

```
from PyQt4 import QtGui, QtCore
import sys
import I2CGenericFrame
import os

class I2CApp(QtGui.QMainWindow, I2CGenericFrame.Ui_winI2CMain):
    def __init__(self):
        super(self.__class__, self).__init__()
        self.setupUi(self)

    self.cmbBusListBox.addItem("Slect ..")

```

It is giving following error.

```
Traceback (most recent call last):
  File "I2cMain.py", line 6, in <module>
    class I2CApp(QtGui.QMainWindow, I2CGenericFrame.Ui_winI2CMain):
  File "I2cMain.py", line 12, in I2CApp
    self.cmbBusListBox.addItem("Slect ..")
NameError: name 'self' is not defined

```

Guide me, Thanks in advance.