Class with Object as a parameter
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.
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.
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.