Week 9

Question 1

You would typically use a for loop to iterate over the elements in a set.

Answer 1

True

Question 2

Sets are immutable.

Answer 2

False

Question 3

Sets are created using curly braces { }.

Answer 3

False

Question 4

The set remove and discard methods behave differently only when a specified item is not found in the set.

Answer 4

True

Question 5

A dictionary can include the same value several times but cannot include the same key several times.

Answer 5

True

Question 6

The union of two sets is a set that contains only the elements that appear in both sets.

Answer 6

False

Question 7

The difference of set1 and aet2 is a set that contains only the elements that appear in set1 but do not appear in set2.

Answer 7

True

Question 8

The elements in a dictionary are stored in ascending order, by the keys of the key-value pairs.

Answer 8

False

Question 9

If you try to retrieve a value from a dictionary using a nonexistent key, a KeyError exception is raised.

Answer 9

True

Question 10

The issubset() method can be used to determine whether set1 is a subset of set2.

Answer 10

True

Question 11

In a dictionary, you use a(n) __________ to locate a specific value.
a. datum
b. element
c. item
d. key

Answer 11

d. key

Question 12

What is the correct structure to create a dictionary of months where each month will be accessed by its month number (for example, January is month 1, April is month 4)?
a. { 1 ; ‘January’, 2 ; ‘February’, … 12 ; ‘December’}
b. { 1 : ‘January’, 2 : ‘February’, … 12 : ‘December’ }
c. [ ‘1’ : ‘January’, ‘2’ : ‘February’, … ‘12’ : ‘December’ ]
d. { 1, 2,… 12 : ‘January’, ‘February’,… ‘December’ }

Answer 12

b. { 1 : ‘January’, 2 : ‘February’, … 12 : ‘December’ }

Question 13

What will be the result of the following code?
ages = {‘Aaron’ : 6, ‘Kelly’ : 3, ‘Abigail’ : 1 }
value = ages[‘Brianna’]
a. False
b. -1
c. 0
d. KeyError

Answer 13

d. KeyError

Question 14

What is the number of the first index in a dictionary?
a. 0
b. 1
c. the size of the dictionary minus one
d. Dictionaries are not indexed by number.

Answer 14

d. Dictionaries are not indexed by number.

Question 15

What is the value of the variable phones after the following code executes?
phones = {‘John’ : ‘5555555’, ‘Julie’ : ‘5557777’}
phones[‘John’] = 5556666’
a. {‘John’ : ‘5555555’, ‘Julie’ : ‘5557777’}
b. {‘John’ : ‘5556666’, ‘Julie’ : ‘5557777’}
c. {‘John’ : ‘5556666’}
d. This code is invalid.

Answer 15

b. {‘John’ : ‘5556666’, ‘Julie’ : ‘5557777’}

Question 16

Which would you use to delete an existing key-value pair from a dictionary?
a. del
b. remove
c. delete
d. unpair

Answer 16

a. del

Question 17

Which would you use to get the number of elements in a dictionary?
a. size
b. length
c. len
d. sizeof

Answer 17

c. len

Question 18

Which method would you use to get all the elements in a dictionary returned as a list of tuples?
a. list
b. items
c. pop
d. keys

Answer 18

b. items

Question 19

Which method would you use to get the value associated with a specific key and remove that key-value pair from the dictionary?
a. list
b. items
c. pop
d. popitem

Answer 19

c. pop

Question 20

Which method can be used to add a group of elements to a set?
a. add
b. addgroup
c. update
d. addset

Answer 20

c. update

Question 21

In order to avoid KeyError exceptions, you can check whether a key is in the dictionary using the __________ operator.
a. included
b. in
c. isnotin
d. isin

Answer 21

b. in

Question 22

What does the get method do if the specified key is not found in the dictionary?
a. It throws an exception.
b. It does nothing.
c. It returns a default value.
d. You cannot use the get method to specify a key.

Answer 22

c. It returns a default value.

Question 23

Which of the following does not apply to sets?
a. The stored elements can be of different data types.
b. All the elements must be unique; you cannot have two elements with the same value.
c. The elements are unordered.
d. The elements are in pairs.

Answer 23

d. The elements are in pairs.

Question 24

What is the process used to convert an object to a stream of bytes that can be saved in a file?
a. pickling
b. streaming
c. writing
d. dumping

Answer 24

a. pickling

Question 25

What will be displayed after the following code executes? (Note: the order of the display of entries in a dictionary are not in a specific order.)
cities = {‘GA’ : ‘Atlanta’, ‘NY’ : ‘Albany’, ‘CA’ : ‘San Diego’}
if ‘CA’ in cities:
del cities[‘CA’]
cities[‘CA’] = ‘Sacramento’
print(cities)
a. {‘CA’: ‘Sacramento’}
b. [‘CA’: ‘Sacramento’]
c. {‘NY’: ‘Albany’, ‘GA’: ‘Atlanta’}
d. {‘CA’: ‘Sacramento’, ‘NY’: ‘Albany’, ‘GA’: ‘Atlanta’}

Answer 25

{‘GA’: ‘Atlanta’, ‘NY’: ‘Albany’, ‘CA’: ‘Sacramento’}

Question 26

What will be displayed after the following code executes? (Note: the order of the display of entries in a dictionary are not in a specific order.)
cities = {‘GA’ : ‘Atlanta’, ‘NY’ : ‘Albany’, ‘CA’ : ‘San Diego’}
if ‘FL’ in cities:
del cities[‘FL’]
cities[‘FL’] = ‘Tallahassee’
print(cities)
a. {‘FL’: ‘Tallahassee’}
b. KeyError
c. {‘CA’: ‘San Diego’, ‘NY’: ‘Albany’, ‘GA’: ‘Atlanta’, ‘FL’ ‘Tallahassee’}
d. {‘CA’: ‘San Diego’, ‘NY’: ‘Albany’, ‘GA’: ‘Atlanta’}

Answer 26

{‘GA’: ‘Atlanta’, ‘NY’: ‘Albany’, ‘CA’: ‘San Diego’}

Question 27

A(n) __________ is an object that holds multiple unique items of data in an unordered manner.

Answer 27

set

Question 28

The built-in function, __________, returns the number of items in a set.

Answer 28

len

Question 29

To add a single item to a set, you can use the set __________ method.

Answer 29

add

Question 30

The __________ of two sets is a set that contains all the elements of both sets.

Answer 30

union

Question 31

Each element in a(n) __________ has two parts: a key and a value.

Answer 31

dictionary

Question 32

The elements in a dictionary are not stored in a specific order. Therefore, a dictionary is not a(n) ___________.

Answer 32

sequence

Question 33

To determine whether or not a key is included in a dictionary, or if an element is included in a set, you can use the ___________ operator.

Answer 33

not in

Question 34

The __________ method returns a value associated with a specific key and, if found, removes that key-value pair from the dictionary.

Answer 34

pop

Question 35

The __________ method clears the contents of a dictionary.

Answer 35

clear

Question 36

To write an object to a file, you use the __________ function of the __________ module.

Answer 36

dump, pickle

Question 37

The __________ method returns all of a dictionary’s keys as a dictionary view.