class A:
    def message(self):
        print('1', end='') 
        
    def __enter__(self):
        print('2', end='') 
        return self
    
    def __exit__(self, exc_type, exc_value, exc_tb):
        if exc_type is None:
            print('3', end='')  
        else:
            print ('4', end='')
            return True   
        
with A() as action:
    action.message()

class Error(Exception): pass

def handle(file):
    raise Error()
    
file = open('mydata', 'w') 

try:
    handle(file)
    print('one')
finally:
    file.close() 

print('two')

class Error(Exception): pass

def handle(file):
    raise Error()
    
file = open('mydata', 'w') 

try:
    handle(file)
    print('one')
finally:
    file.close() 

print('two')

sum([3 >> i for i in range(200)])

val = # ваш код
shoes = {'name': 'fashion shoes', 'price': 14900}
def discount(item, discount):
    price = int(item['price']) * (1.0 - discount)
    assert 0 <= price <= item['price']
    return price
discount(shoes, val)

class MyExc(Exception):
    def __str__(self): 
        return 'my-exc'
try:
    raise MyExc()
    print('try')
except MyExc as err:
    print(err)
else:
    print('else')

class A:
    def __enter__(self):
        print('1', end='')
        return None
    def __exit__(self, exc_type, exc_value, exc_tb):
        if exc_type is None:
            print('3', end='')  
        else:
            print ('4', end='')
            return True
    
with A() as a:
    print("2" if a else "3", end='')
    raise Exception
    print("5", end="")

{k.upper() : k * 2 for k in [ 'hello', 'hi', 'good morning' ] if k[0] == 'h'}

_  = dict((x, x * x) for x in range(10))
print(x)

type({x * x for x in range(10)})

def f(*seqs, pad=None):
    seqs = [list(S) for S in seqs]
    while any(seqs):
        yield tuple((S.pop(0) if S else pad) for S in seqs)
s1, s2 = '987', 'xy'
print(list(f(s1, s2)))