menu = {
    'pita' : 1,
    'steak' : 150,
    'hamburger' : 59,
    'pizza' : 40,
    'cola' : 12
}

for item in menu.keys():
    price = menu[item]
    menu[item] = menu[item] * 1.1

print(menu)

{'pita': 1.1, 'steak': 165.0, 'hamburger': 64.9, 'pizza': 44.0, 'cola': 13.200000000000001}

for keyvalue in menu.items():
    item, price = keyvalue
    menu[item] = price * 1.1

('pita', 1.1)
('steak', 165.0)
('hamburger', 64.9)
('pizza', 44.0)
('cola', 13.200000000000001)

print(menu)

{'pita': 1.2100000000000002, 'steak': 181.50000000000003, 'hamburger': 71.39000000000001, 'pizza': 48.400000000000006, 'cola': 14.520000000000003}

for item, price in menu.items():
    menu[item] = price * 1.1

print(menu)

{'pita': 1.3310000000000004, 'steak': 199.65000000000003, 'hamburger': 78.52900000000002, 'pizza': 53.24000000000001, 'cola': 15.972000000000005}

menu

{'pita': 1.3310000000000004,
 'steak': 199.65000000000003,
 'hamburger': 78.52900000000002,
 'pizza': 53.24000000000001,
 'cola': 15.972000000000005}

menu[0]

    ---------------------------------------------------------------------------

    KeyError                                  Traceback (most recent call last)

    <ipython-input-10-ca462d9b1d0b> in <module>
    ----> 1 menu[0]
    
    KeyError: 0

menu['shkashuka'] = 100

menu

{'pita': 1.3310000000000004,
 'steak': 199.65000000000003,
 'hamburger': 78.52900000000002,
 'pizza': 53.24000000000001,
 'cola': 15.972000000000005,
 'shkashuka': 100}

menu.pop('cola')

15.972000000000005

menu

{'pita': 1.3310000000000004,
 'steak': 199.65000000000003,
 'hamburger': 78.52900000000002,
 'pizza': 53.24000000000001,
 'shkashuka': 100}

print(menu.get('cats', "Sorry not on menu"))

Sorry not on menu

menu.get('pita', "Sorry not on menu")

1.3310000000000004

menu.setdefault('pita', "Sorry not on menu")

1.3310000000000004

menu

{'pita': 1.3310000000000004,
 'steak': 199.65000000000003,
 'hamburger': 78.52900000000002,
 'pizza': 53.24000000000001,
 'shkashuka': 100}

menu.setdefault('cats', "Sorry not on menu")

'Sorry not on menu'

menu

{'pita': 1.3310000000000004,
 'steak': 199.65000000000003,
 'hamburger': 78.52900000000002,
 'pizza': 53.24000000000001,
 'shkashuka': 100,
 'cats': 'Sorry not on menu'}

p144 = {
    'avi' : 1,
    'ben' : 2,
    "gaddy" : 3,
    "david" : 4,
    "efrat" :4
    
}

p441 = {}
for name, phone in p144.items():
    p441[phone] = name

print(p441)

{1: 'avi', 2: 'ben', 3: 'gaddy', 4: 'david'}

p441 = {}
for name, phone in p144.items():
    if phone in p441:
        list_of_names = p441[phone]
        list_of_names.append(name)
    else:
        p441[phone] = [ name ]

p441 = {}
for name, phone in p144.items():
    if phone in p441:
        p441[phone].append(name)
    else:
        p441[phone] = [ name ]

p441 = {}
for name, phone in p144.items():
    p441.setdefault(phone, []).append(name)

p441={}, name=avi, phone=1
p441={1: ['avi']}, name=ben, phone=2
p441={1: ['avi'], 2: ['ben']}, name=gaddy, phone=3
p441={1: ['avi'], 2: ['ben'], 3: ['gaddy']}, name=david, phone=4
p441={1: ['avi'], 2: ['ben'], 3: ['gaddy'], 4: ['david']}, name=efrat, phone=4

p441

{1: ['avi'], 2: ['ben'], 3: ['gaddy'], 4: ['david', 'efrat']}