Class with Object as a parameter

I'm trying to translate some python code to scala code. So I'm a total noob in Python.

But why do some classes have object as a parameter but never explicitly use it? What's the reasoning for having it as a parameter in the first place?

Example:

class Table(object)

Thank you for your time.

Solution 1:

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.

Solution 2:

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.

Solution 3:

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.