from itertools import islice

def infinite_seq():
    n = 1
    while True:
        yield n
        n *= 2

gen = infinite_seq()
result = list(islice(gen, 5))
print(sum(result))

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

for i in range(3):
    if i == 1:
        continue
    print(i, end="")

a, *b, c = [1, 2, 3, 4, 5]
print(b)

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

n = 3
while n > 0:
    n -= 1
    if n == 1:
        break
else:
    print("A", end=" ")
print(n)

x = [1, 2]
def f():
    x += [3]

try:
    f()
except UnboundLocalError:
    print("Error")

print(True * 3 == 3, False + 5 == 5)

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)