Question

which of the following is the correct way to call the add_course method in the student class? the variable my_student is defined as follows: my_student = student() a add_course(my_student, 231) b my_student.add_course(my_student, 231) c my_student.add_course(self, 231) d my_student.add_course(231)

Explanation:

Step1: Understand method calling in Python

In Python, when you have an object (here my_student which is an instance of Student class), to call a method of that class, you use the syntax object.method(). The self parameter in a class method is automatically passed as the instance itself when the method is called via the object. So when you do my_student.add_course(), the my_student instance is passed as the self argument internally.

Step2: Analyze each option

• Option A: add_course(my_student, 231): This is incorrect. If add_course is a method of the Student class, it should be called on the instance (using dot notation) rather than being called as a standalone function with the instance as the first argument.
• Option B: my_student.add_course(my_student, 231): This is wrong. Since my_student is already the instance, when you call my_student.add_course(), Python internally passes my_student as the self argument. Passing it again explicitly is redundant and incorrect.
• Option C: my_student.add_course(self, 231): This is incorrect. self is a convention for the first parameter of a class method (representing the instance). But when calling the method via the instance (my_student), you don't pass self explicitly. self is filled by Python with the instance (my_student).
• Option D: my_student.add_course(231): This is correct. Here, my_student is the instance of the Student class. When you call my_student.add_course(231), Python passes my_student as the self argument to the add_course method (as per the class - method calling convention) and 231 as the other argument (assuming 231 is the correct argument for the add_course method).

Answer:

D. my_student.add_course(231)