Why class method must have self parameter in python?

Question

class Student:
    def __init__(self, name):
        self.name = name

I know why self is used in this code. This can take different students and make differnt attributes

student1 = Student()
student2 = Student()
...
studentn = Student()
------------------------------------

student1.name
student2.name
...
studentn.name

but I can't understand why this code below needs self parameter.

class Student:
    def study():
        print("I'm studying")


Student().study()

output

Traceback (most recent call last):
  File "C:/directory/test.py", line 12, in <module>
    Student().study()
TypeError: study() takes 0 positional arguments but 1 was given

Answer 1

Because methods are passed the instance they're called on, regardless of if the method needs it or not.

If you don't want to need to have the parameter, make it a "static method":

class Student:
    @staticmethod
    def study():
        print("I'm studying")

Answer 2

The first argument of every class method, including init, is always a reference to the current instance of the class. By convention, this argument is always named self. In the init method, self refers to the newly created object; in other class methods, it refers to the instance whose method was called

More on the self variable here