WorksheetsPython Dictionaries
Total questions: 10
Worksheet time: 8mins
Which of the following are true of Python dictionaries:
Dictionaries can be nested to any depth.
Dictionaries are accessed by key.
All the keys in a dictionary must be of the same type.
Dictionaries are mutable.
A dictionary can contain any object type except another dictionary.
Which of the following is not a valid way to define this dictionary in Python:
d = dict([
('foo', 100),
('bar', 200),
('baz', 300)
])
d = {}
d['foo'] = 100
d['bar'] = 200
d['baz'] = 300
d = dict(foo=100, bar=200, baz=300)
d = {'foo': 100, 'bar': 200, 'baz': 300}
d = { ('foo', 100), ('bar', 200), ('baz', 300) }
Consider this dictionary:
d = {'foo': 100, 'bar': 200, 'baz': 300}
What is the result of this statement:
d['bar':'baz']
It raises an exception
(200, 300)
200 300
[200, 300]
Suppose x is defined as follows:
x = [
'a',
'b',
{
'foo': 1,
'bar':
{
'x' : 10,
'y' : 20,
'z' : 30
},
'baz': 3
},
'c',
'd'
]
What is the expression involving x that accesses the value 30?
x[2]["bar"]["z"]
x[2]["bar"]
x["bar"]["z"]
x[2]["bar"]["z"][3]
Which of the following could be a valid dictionary key:
(3+2j)
('foo', 'bar')
dict(foo=1, bar=2)
'foo'
['foo', 'bar']
You have the following dictionary definition:
d = {'foo': 100, 'bar': 200, 'baz': 300}
What method call will delete the entry whose value is 200?
delete d('bar')
d.pop("bar")
d.remove("bar")
None of the above
Suppose you have a dictionary d1. Which of the following effectively creates a variable d2 which contains a copy of d1:
d2 = dict(d1.items())
d2 = dict(d1.keys())
d2 = {}
d2.update(d1)
d2 = dict(d1.values())
d2 = dict(d1)
What would be the output of the following code snippet?
a_dict = {'color': 'blue', 'fruit': 'apple', 'pet': 'dog'}
for key in a_dict:
print(key)
'blue'
'apple'
'dog'
color
fruit
pet
blue
apple
dog
'color'
'fruit'
'pet'
What would be the output of the following code snippet?
a_dict = {'color': 'blue', 'fruit': 'apple', 'pet': 'dog'}
d_items = a_dict.items()
print(d_items)
('color', 'blue'), ('fruit', 'apple'), ('pet', 'dog')
dict_items([('color'), ('fruit'), ('pet')])
[('color', 'blue'), ('fruit', 'apple'), ('pet', 'dog')]
dict_items([('color', 'blue'), ('fruit', 'apple'), ('pet', 'dog')])
Consider the following statement:
If you just need to work with the keys of a dictionary, then you can use .keys(), which is a method that returns a new view object containing the dictionary’s keys.
Is this statement True or False?
False
True
