Class Method and Static Method in Python

example.py

class Student:
    def __init__(self, first_name, last_name):
        self.first_name = first_name
        self.last_name = last_name
        self.nickname = None

    def set_nickname(self, name):
        self.nickname = name

    @classmethod # get_from_string is a class method
    def get_from_string(cls, name_string: str):
        first_name, last_name = name_string.split()
        return Student(first_name, last_name)


s = Student.get_from_string('yang    zhou')
print(s.first_name)  # yang
print(s.last_name)  # zhou

# can't call instance method directly by class name
s2 = Student.set_nickname('yang') 
# TypeError: set_nickname() missing 1 required positional argument: 'name'

line13: you should just inject the attributes directly into the constructor with cls:

class Student:
    def __init__(self, first_name, last_name):
        self.first_name = first_name
        self.last_name = last_name
        self.nickname = None

    def set_nickname(self, name):
        self.nickname = name

    @classmethod
    def from_string(cls, name_string: str):
        first_name, last_name = name_string.split()
        return cls(first_name, last_name)