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Python Object-Oriented Python (retired) Objects Create a Class with a Method

James J. McCombie
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James J. McCombie
Python Web Development Techdegree Graduate 21,199 Points
Posted by James J. McCombie
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James J. McCombie
Python Web Development Techdegree Graduate 21,199 Points

method.py

method, as a function, works in IDE shell, but wont pass in the quiz:

class Store: open = 9 close = 5

def hours(open, close):
    return "We're open from {} to {}.".format(open, close)

anyone know why

method.py 
class Store:
    open = 9
    close = 5

    def hours(open, close):

        return "We're open from {} to {}.".format(open, close)

3 Answers

Chris Freeman
MOD
Chris Freeman
Treehouse Moderator 68,454 Points
Chris Freeman
Chris Freeman
Treehouse Moderator 68,454 Points

When defining a class method, it needs to refer to the class instance it is bound to. This is what allows the method to refer to the class and instance attributes. The reference is designated by the self parameter:

class Store:
    open = 9
    close = 5

    def hours(self):  # <-- add 'self' to parameter list. 'close' and 'open' are not needed
        # refer to attributes by using the 'self.' prefix to access 'open' and 'close'
        return "We're open from {} to {}.".format(self.open, self.close)
Steve Hunter
Steve Hunter
57,712 Points
Steve Hunter
Steve Hunter
57,712 Points

Hi James,

You don't need to pass the open and close instance variables into the method; try with just the instance itself, self.

You can then use this to access the instance variables:

Store.py 
class Store:
  open = 9
  close = 5
  def hours(self):
    return "We're open from {} to {}.".format(self.open, self.close)

I hope that makes sense.

Steve.

Steve Hunter
Steve Hunter
57,712 Points

Haha! Thank you!! edits post :wink:

James J. McCombie
seal-mask
.a{fill-rule:evenodd;}techdegree seal-36
James J. McCombie
Python Web Development Techdegree Graduate 21,199 Points
James J. McCombie
.a{fill-rule:evenodd;}techdegree seal-36
James J. McCombie
Python Web Development Techdegree Graduate 21,199 Points

Thank you both, obvious from the lesson content in hindsight, but you have made it stick now, thanks, is it better to sometimes just accept the way things have to be written even though you are still a little confused about why...perhaps it will make sense to me one day.

Steve Hunter
Steve Hunter
57,712 Points

I think that continued exposure to these concepts make them easier to understand as you work through the courses. Keep at it - it does all come together in the end!

proofreads :wink: