Can use the class name directly (e.g., Student) instead of using cls in class methods

es, you can use the class name directly (e.g., Student) instead of using cls in class methods, but using cls is generally preferred for a few important reasons. Here’s why:

1. Flexibility with Inheritance:

When you use cls in a class method, you’re referring to the class that the method was called on, which could be a subclass. This provides flexibility, as the method can work correctly with subclasses as well, not just the Student class.

Example of Using cls:

class Student:
    number_of_students = {1: 10, 2: 20, 3: 60, 4: 12}

    @classmethod
    def get_number_of_students_class(cls, grade: int):
        # Uses cls, making it compatible with subclasses
        return cls.number_of_students.get(grade, 0)

Now, if you create a subclass of Student, it will inherit the get_number_of_students_class method, and cls will refer to the subclass:

class HighSchoolStudent(Student):
    number_of_students = {1: 50, 2: 100, 3: 150, 4: 200}

# This will use HighSchoolStudent.number_of_students because `cls` refers to the subclass
print(HighSchoolStudent.get_number_of_students_class(3))  # Output: 150

If you hardcode Student instead of cls, this flexibility would be lost, and the method would always use Student‘s attributes, even when called on a subclass.

2. Readability and Conventions:

Using cls in a @classmethod is a standard Python convention. Just like using self for instance methods, cls makes it clear that the method is operating at the class level. It improves code readability for other developers who expect cls in class methods.

Using Class Name (Student) Directly:

While using the class name directly works, it binds the method to the specific class, which could limit flexibility with inheritance. Here’s how it would look:

class Student:
    number_of_students = {1: 10, 2: 20, 3: 60, 4: 12}

    @classmethod
    def get_number_of_students_class(cls, grade: int):
        # You can replace cls with Student, but it's less flexible
        return Student.number_of_students.get(grade, 0)

In this case, calling the method on a subclass will still reference Student‘s number_of_students, regardless of what HighSchoolStudent has.

Example:

class HighSchoolStudent(Student):
    number_of_students = {1: 50, 2: 100, 3: 150, 4: 200}

# This will still use Student.number_of_students, not HighSchoolStudent
print(HighSchoolStudent.get_number_of_students_class(3))  # Output: 60 (from Student)

Conclusion:

• Using cls is preferred for flexibility, especially when subclassing.
• Using Student directly works but ties the method to the Student class, limiting flexibility with subclasses.

If you don’t expect your class to be subclassed or don’t care about inheritance, using the class name directly is fine, but using cls is a better long-term practice.