What exactly happens when i don't use "self" key while initialising a variable like m1 inside a class method. m1 is local,object or class variable?

class Student:
    def __init__(self,m1,m2):
        m1=m1
        m2=m2
        print(m1+m2)

s1=Student(10,20)
s2=Student(20,30)

print(Student.m1)

#i have just started the oops concepts so am a little confused now. when writing "print(Student.m1) or print(s1.m1)" am getting compile time error as
"AttributeError: type object ‘Student’ has no attribute ‘m1’".

>Solution :

If you don’t use self, you are just assigning the value to a local variable which cannot be accessed once the function has finished.

If you use self.m1, the value is assigned to an attribute of self, and can later be accessed.