A class is useless if it has not defined any functionality. We can do so by adding attributes. They work as containers for data and functions. We can add an attribute directly specifying inside the class body in Python.
>>> class Human:
... profession = "programmer" # specify the attribute 'profession' of the class
>>> man = Human()
>>> print(man.profession)
programmer
After we added the attributes, we can go on to define the functions. Generally, we call them methods. In the method signature, we always have to provide the first argument with a self-keyword.
>>> class Human:
profession = "programmer"
def set_profession(self, new_profession):
self.profession = new_profession
>>> man = Human()
>>> man.set_profession("Manager")
>>> print(man.profession)
Manager