Ch9 Dictionaries And Sets Complete Test Bank

Starting Out with Python 5e (Gaddis)

Chapter 9 Dictionaries and Sets

TRUE/FALSE

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

2. Sets are immutable.

3. Sets are created using curly braces { }.

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

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

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

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.

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

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

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

11. A set comprehension is written just like a list comprehension, except that a set comprehension is enclosed in angled brackets (<>), and a list comprehension is enclosed in square brackets ([]).

MULTIPLE CHOICE

1. In a dictionary, you use a(n) __________ to locate a specific value.

2. 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)?

3. What will be the result of the following code?

ages = {'Aaron' : 6, 'Kelly' : 3, 'Abigail' : 1 }

value = ages['Brianna']

4. What is the number of the first index in a dictionary?

5. What is the value of the variable phones after the following code executes?

phones = {'John' : '5555555', 'Julie' : '5557777'}

phones['John'] = 5556666'

6. Which would you use to delete an existing key-value pair from a dictionary?

7. Which would you use to get the number of elements in a dictionary?

8. Which method would you use to get all the elements in a dictionary returned as a list of tuples?

9. Which method would you use to get the value associated with a specific key and remove that key-value pair from the dictionary?

10. What values will d2 contain after the following code executes?

d = {1: 10, 2: 20, 3: 30}

d2 = {k:v for k,v in d.items()}

a. {10: 1, 20: 2, 30: 3}

b. {1: 1, 2: 2, 3: 3}

c. {10: 10, 20: 20, 30: 30}

d. {1: 10, 2: 20, 3: 30}

11. Which method can be used to add a group of elements to a set?

12. In order to avoid KeyError exceptions, you can check whether a key is in the dictionary using the __________ operator.

13. What does the get method do if the specified key is not found in the dictionary?

14. Which of the following does not apply to sets?

15. What is the process used to convert an object to a stream of bytes that can be saved in a file?

16. 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)

17. 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)

18. 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)

COMPLETION

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

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

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

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

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

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

7. 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.

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

9. The __________ method clears the contents of a dictionary.

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

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

12. Each element in a dictionary view is a __________.