what is self._base?

[maxm]

"Benjamin Tai" <bt98 at doc.ic.ac.uk> wrote in message
news:3C19EC50.153B76A1 at doc.ic.ac.uk...

> However I can't find any documents/explanation for the following:
>
> 1) What is  "_base"

"_base" is an attribute on the object that can contain any Python objects.
It could alse be called base, Base, __base etc. The leading underscore
indicates that it is a private attribute, that should only be used by the
class itself. This is just a convention, and is not enforced by the
language.

So even though you shouldn't you could call it via:

stack = Stack()
print stack._base
>>> some_kind_of_stack_object

> 2) What is  "start=None"

It is a default parameter passed to the __init__ method. It means that it
has not been assigned a more meaningfull value.

If you create the object with a parameter, you could do it like:

stack = Stack('Spam egg')
print stack._base
>>> Spam egg

or like this which is in effect the same.

stack = Stack(start='Spam egg')
print stack._base
>>> Spam egg

> 3) Why can't I just write  "self = stacktype.Stack()"

Oh but you can ... it would just not do what you excpect ;-)

What if you have more than one attribute. How would you call them then.

ie.::

self = 'Max M'
self = 'Rasmussen'
self = 'Denmark'

self.firstName = 'Max M'
self.lastname = 'Rasmussen'
self.country = 'Denmark'

Without the attribute name you could not adress the values again. And by
setting self to a string or any other object you are in effect changing the
object to something else.

I would recommend that you get a hold of the excellent "Learning Python"
book, that does a great job at explaining the fundemantals of Python. It
will save you a lot of time in the long run.

regards Max M