Delegates Decorator

My study of the `@delegates` decorator and `GetAttr` from `fastcore`.

I follow https://www.fast.ai/posts/2019-08-06-delegation.html

class Person:
    def __init__(self, name, age):
        self.name = name
        self.age = age

class Student(Person):
    def __init__(self, name, age, grade):
        super().__init__(name, age)
        self.grade = grade

student = Student("Alice", 12, 'A')
print(student.name, student.age, student.grade)

kid = Student("Uma", 5.5, 'Good Kid!')
print(kid.name, kid.age, kid.grade)

%pip install fastcore

from fastcore.meta import delegates

class Person:
    def __init__(self, name, age, **kwargs):
        self.name = name
        self.age = age

@delegates()
class Student(Person):
    def __init__(self, name, age, grade, **kwargs):
        super().__init__(name, age, **kwargs)
        self.grade = grade

child = Student("Amira", 6, grade='A', school='XYZ')
child.__dict__

from fastcore.basics import GetAttr

class Strawberry(GetAttr):
    def __init__(self, color, variety):
        self.color, self.variety = color, variety
        self.default = color

s = Strawberry('red', 'Pegasus')
s.color, s.variety, s.default

[s for s in dir(s) if not s.startswith('_')]

def play(game, player='Daddy', num_players=2):
    print(f'{player} is playing {game}')

play('chess', 'Mehdiya')

@delegates(play)
def play_chess(player, speed='blitz', **kwargs):
    play('chess', player)

play_chess('Uma')

print(play_chess.__signature__)

import inspect
print(inspect.signature(play_chess))

print(inspect.signature(play))