d = {'a': 1, 'b': 2, 'c': 3}
try:
    for k in d:
        del d[k]
    print(len(d))
except RuntimeError:
    print("RuntimeError")

lst = [x for x in range(10) if x % 2 == 0 if x % 3 == 0]
print(lst)

class Model:
    val = 1
    lst = [val for _ in range(3)]

print(Model.lst)

x = 10
def f():
    print(x)
    x = 20
f()

data = [5, 10, 15, 20]
data.extend([x // 2 for x in data[:2]])
print(sum(data))

def add_item(num, lst=[]):
    lst.append(num)
    return lst

add_item(1)
print(add_item(2))

def calculate(x, y):
    if x > y:
        return x - y
    else:
        return y - x

result = calculate(10, 15) + calculate(20, 8)
print(result)

class A:
    x = 1

class B(A):
    pass

class C(A):
    pass

B.x = 2
A.x = 3

print(C.x)

res = map(lambda x: x * 2, [1, 2])
print(list(res))

class A:
    def __new__(cls):
        return 42
        
    def __init__(self):
        print("Init")

print(A())

d = {'a': 1, 'b': 2, 'c': 3}
try:
    for k in d:
        del d[k]
    print(len(d))
except RuntimeError:
    print("RuntimeError")