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

Eoin Kilbride
Eoin Kilbride
4,705 Points
Posted by Eoin Kilbride
Eoin Kilbride
4,705 Points

Create Class Challenge

This code won't run- why? In the editor, open is a different color to close which makes me think there's some issue with using the word "open" as an attribute name

class Store: open = 9 close = 5.30

method.py 
class Store:
  open = 9
  close = 5.30
Sharad Shivmath
Sharad Shivmath
14,446 Points

Sorry I haven't done the challenge, but I am fairly comfy with Python. I usually define a class like this: 

class Store:
    def __init__(self, open, close):
        self.open = open
        self.close = close

Hope it helps.

1 Answer

Chris Freeman
MOD
Chris Freeman
Treehouse Moderator 68,423 Points
Chris Freeman
Chris Freeman
Treehouse Moderator 68,423 Points

Your first Store class passes Task one of the challenge. The second Store class (in comment) does not pass the challenge because it defines instance attributes instead of class attributes. What do you mean by "Won't run"?

The word open is highlighted differently because it is a built-in function. While it could be used as a variable name, using built-in or reserved names as variables is not a good practice. But since the challenge is expecting "open" you're stuck with it. A better choice would be "open_time".

Also, it is customary to put an empty pair of parens after the class name definition. It is recommend in the PEP-0008 style guild to use 4-space indentation.

class Store():  #<-- added parens
    open = 9  #<-- increased indentation
    close = 5.30 #<-- This is 5 and 3/10 hours

Both of your code samples run in the interpreter:

# First Store
>>> class Store:
...   open = 9
...   close = 5.30
... 
>>> my_store = Store()
# Instance dict
>>> my_store.__dict__
{}
# class dict
>>> Store.__dict__
mappingproxy({'open': 9, '__doc__': None, 'close': 5.3, '__dict__': <attribute '__dict__' of 'Store' objects>, '__weakref__': <attribute '__weakref__' of 'Store' objects>, '__module__': '__main__'})

>>> dir(my_store)
['__class__', '__delattr__', '__dict__', '__dir__', '__doc__', '__eq__', '__format__', '__ge__', '__getattribute__', '__gt__', '__hash__', '__init__', '__le__', '__lt__', '__module__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__', '__weakref__', 'close', 'open']
>>> my_store.open
9
>>> my_store.close
5.3
>>> 
>>> 
# Second Store
>>> class Store:
...     def __init__(self, open, close):
...         self.open = open
...         self.close = close 
... 
>>> other_store = Store(open=8, close=6)
# instance dict
>>> other_store.__dict__
{'open': 8, 'close': 6}
# class dict
>>> Store.__dict__
mappingproxy({'__weakref__': <attribute '__weakref__' of 'Store' objects>, '__doc__': None, '__dict__': <attribute '__dict__' of 'Store' objects>, '__init__': <function Store.__init__ at 0x7f624120d6a8>, '__module__': '__main__'})

>>> dir(other_store)
['__class__', '__delattr__', '__dict__', '__dir__', '__doc__', '__eq__', '__format__', '__ge__', '__getattribute__', '__gt__', '__hash__', '__init__', '__le__', '__lt__', '__module__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__', '__weakref__', 'close', 'open']
>>> other_store.open
8
>>> other_store.close
6