Class with Object as a parameter
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Track title: CC P Beethoven - Piano Sonata No 2 in A
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Chapters
00:00 Question
00:35 Accepted answer (Score 152)
01:53 Answer 2 (Score 37)
02:37 Answer 3 (Score 4)
03:01 Answer 4 (Score 3)
03:19 Thank you
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Full question
https://stackoverflow.com/questions/7375...
Accepted answer links:
[new-style class]: http://www.python.org/doc/newstyle/
[properties]: http://www.python.org/download/releases/...
[super]: http://docs.python.org/library/functions...
Answer 2 links:
[see this question]: https://stackoverflow.com/questions/5486.../
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Content licensed under CC BY-SA
https://meta.stackexchange.com/help/lice...
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Tags
#python
#avk47
ACCEPTED ANSWER
Score 152
In Python2 this declares Table to be a new-style class (as opposed to "classic" class).
In Python3 all classes are new-style classes, so this is no longer necessary.
New style classes have a few special attributes that classic classes lack.
class Classic: pass
class NewStyle(object): pass
print(dir(Classic))
# ['__doc__', '__module__']
print(dir(NewStyle))
# ['__class__', '__delattr__', '__dict__', '__doc__', '__format__', '__getattribute__', '__hash__', '__init__', '__module__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__', '__weakref__']
Also, properties and super do not work with classic classes.
In Python2 it is a good idea to make all classes new-style classes. (Though a lot of classes in the standard library are still classic classes, for the sake of backward-compatibility.)
In general, in a statement such as
class Foo(Base1, Base2):
Foo is being declared as a class inheriting from base classes Base1 and Base2.
object is the mother of all classes in Python. It is a new-style class, so inheriting from object makes Table a new-style class.
ANSWER 2
Score 37
The Table class is extending a class called object. It's not an argument. The reason you may want to extend object explicitly is it turns the class into a new-style class. If you don't explicitly specify it extends object, until Python 3, it will default to being an old-style class. (Since Python 3, all classes are new-style, whether you explicitly extend object or not.)
For more information on new-style and old-style classes, please see this question.
ANSWER 3
Score 4
class Table and class Table(object) are no different for Python.
It's not a parameter, its extending from object (which is base Class like many other languages).
All it says is that it inherits whatever is defined in "object". This is the default behaviour.
ANSWER 4
Score 3
Just a note that the “new-style" vs “old-style” class distinction is specific to Python 2.x; in 3.x, all classes are “new-style”.