class Meta(type):
    def __new__(cls, name, bases, dct):
        dct['greeting'] = 'Hello from metaclass'
        return super().__new__(cls, name, bases, dct)

class A(metaclass=Meta):
    pass

a = A()
print(a.greeting)

def join(*args, sep="-"):
    return sep.join(args)

print(join("a", "b", "c", sep="|"))

def make_funcs():
    return [lambda x: i * x for i in range(3)]

funcs = make_funcs()
print([f(2) for f in funcs])

def decorator(fn):
    def wrapper():
        return "Decorated " + fn()
    return wrapper

@decorator
def say():
    return "Hello"

print(say())

def apply(func, value):
    return func(value)

print(apply(abs, -5))

x = [(lambda y: y ** 2)(i) for i in range(3)]
print(x)

x = [(lambda y: y ** 2)(i) for i in range(3)]
print(x)

def show(a, b=2, *args, c=3, **kwargs):
    return a, b, args, c, kwargs

print(show(1, 5, 6, 7, c=10, d=20))

def outer():
    x = 1
    def inner():
        nonlocal x
        x += 1
        return x
    return inner

f = outer()
print(f(), f())

def repeat(n):
    def decorator(func):
        def wrapper(*args, **kwargs):
            return [func(*args, **kwargs) for _ in range(n)]
        return wrapper
    return decorator

@repeat(3)
def greet(name):
    return f"Hi, {name}"

print(greet("Leo"))

from functools import partial

def power(base, exponent):
    return base ** exponent

square = partial(power, exponent=2)
print(square(4))