Использование списков в конструкторе __init__

class TestClass:
    def __init__(self):
        list = []

class TestClass:
    list = []
    def __init__(self):
        pass

class Person:
 
    def __init__(self, name, age):
        self.name = name
        self.age = age
        self.known_persons = []
 
    def know (self, person):
        if not person in self.known_persons:
            self.known_persons.append(person)
        else:
            print('{} уже знает человека по имени {}'.format(self.name, person.name))
 
    def is_known(self, person):
        text_action = {True: 'знает человека по имени', False : 'не знает человека по имени'}
        is_known_person = person in self.known_persons
        print('{} {} {}'.format(self.name, text_action[is_known_person], person.name))
 
if __name__ == '__main__':
    anna = Person('Anna Ross', 25)
    cliff = Person('Cliff Birds', 45)
    jhon = Person('Jhon Smit', 37)
    
    anna.is_known(cliff)
    anna.know(cliff)
    anna.is_known(cliff)
    anna.know(cliff)
    anna.is_known(jhon)
    anna.know(jhon)
    anna.is_known(jhon)
    anna.know(jhon)

from dataclasses import dataclass, field
from statistics import mean
from typing import List
 
 
@dataclass
class Student:
    name: str
    surname: str
    scores: List[int] = field(default_factory=list)
    
    def avg(self):
        return mean(self.scores)
        
u = Student("Arman", "Hakobyan", [2, 4, 6, 5, 3])
assert u.avg() == 4