[Tutor] Question about Classes

Alan Gauld alan.gauld at blueyonder.co.uk
Tue Nov 25 18:00:36 EST 2003


> > Since the Email class seems to collect emails (plural), it
seems
> > it would be better to call is "Emails". If you use it through
> > an "emails" attribute in the Contact, ...
> > class Emails:
> >     def __init__(self):
> >         self._emails=[]

_emails is an attribute of the Email class.

> >     def show(self):
> >     def add(self, email, type):
> >
> >> class Contact(Email):
> >> def __init__(self...
> >> self.firstName=firstName
> >> self.lastName=lastName
> >                  self.emails = Emails()

emails is an attribute of the Contact class

> > p.emails.add('x', 'yyy')

Which adds an entry to the Emails class in the p contact

> You lost me here. In the preceding section you
> define _email and yet you refer to email in this
> last bit. Does the underscore perform some sort of magic?

Not really its just a convention to indicate in internal
member of a class. The real point is that Magnis has
declared two different variables, one in the Emails
class(_emails) and one in the Contact class(emails).

HTH,

Alan G
Author of the Learn to Program web tutor
http://www.freenetpages.co.uk/hp/alan.gauld

PS. Welcome back to the tutor list Magnus




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