for i in range(3):
    if i == 5:
        break
else:
    print("A", end="")
print("B", end="")

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

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

with Context() as c:
    raise ValueError()

print(c)

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

gen = (x for x in range(3))
list(gen)
print(list(gen))

tpl = ([],)
tpl[0].extend([1, 2])
print(tpl)

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

add_item(1)
print(add_item(2))

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

add_item(1)
print(add_item(2))

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

print(Model.lst)

x = [1, 2, 3, 4, 5]
x[::2] = [10, 20, 30]
print(x)