print(isinstance(True, int))

class MetaCounter(type):
    instances = 0
    
    def __call__(cls, *args, **kwargs):
        MetaCounter.instances += 1
        return super().__call__(*args, **kwargs)

class A(metaclass=MetaCounter):
    pass

class B(A):
    pass

a1, a2 = A(), A()
b1 = B()
print(MetaCounter.instances)

animals = ['кот', 'собака', 'птица', 'рыба']
animals.pop(1)
animals.insert(2, 'хомяк')
print(animals[-2])

print(bool("False"))

class Context:
    def __enter__(self):
        return "A"
    def __exit__(self, *args):
        return True

with Context() as c:
    raise ValueError()

print(c)

def make_counter():
    count = 0
    def increment():
        nonlocal count
        count += 1
        return count
    return increment

c1 = make_counter()
c2 = make_counter()
c1()
print(c1(), c2())

a = [1, 2, 3]
a[1:1] = [4, 5]
print(a)

data = {1: "A", True: "B"}
print(data[1])

print(round(1.5), round(2.5))

gen = (x for x in range(3))
a = list(gen)
b = list(gen)
print(a, b)

x = "global"
res = [x for x in ["local", "scope"]]
print(x)