While it might not be syntactically incorrect to use the empty parentheses in a class definition, parentheses after a class definition are used to indicate inheritance, e.g:
class A(baseClass):
...
In Python, the preferred syntax for a class declaration without any base classes is simply:
class A:
...
Don’t use parentheses unless you are subclassing other classes.
The docs on the matter should give you a better understanding of how to declare and use classes in Python.