[Tutor] What does parent=0 mean?

Danny Yoo dyoo at hkn.eecs.berkeley.edu
Tue Aug 24 21:26:28 CEST 2004

On Tue, 24 Aug 2004, Klas Marteleur wrote:

> I am going thru theGUI programing chapter in Alans latest web tutorial. And
> found this example:

> -----------------------------------------
> from Tkinter import *
> class ClearApp:
>    def __init__(self, parent=0):
>       self.mainWindow = Frame(parent)
>       # Create the entry widget

[code cut]

> What does parent=0 mean?

Hi Klas,

This is an example of a default parameter.  Python allows us to declare
default values for the parameters of a function.  For example:

>>> def sayHello(name="Klas"):
...     print "hello", name
>>> sayHello()
hello Klas
>>> sayHello('dyoo')
hello dyoo

So if we don't pass a parameter off, Python uses the default value. The
Python Tutorial talks about this in section 4.7.1. "Default Argument


Hope this helps!

More information about the Tutor mailing list