03 | Dictionaries Questions Bank
True/False
1. You would typically use a for loop to iterate over the elements in a Dictionary.
2. Sets and dictionaries are both created using curly braces { }.
3. A dictionary can include the same value several times but cannot include the same key several times.
4. The elements in a dictionary are stored in ascending order, by the keys of the key-value pairs.
5. If you try to retrieve a value from a dictionary using a nonexistent key, a KeyError exception is raised.
6. When merging two dictionaries with the merge operator, if the same key appears in both dictionaries, the new dictionary will keep the value from the dictionary on the right-hand side of the operator.
Multiple Choice
1. In a dictionary, you use a(n) __________ to locate a specific value. a. datum b. element c. item d. key
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)?
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'}
3. 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
4. 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.
5. 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.
6. Which would you use to delete an existing key-value pair from a dictionary?
a. del
b. remove
c. delete
d. unpair
7. Which would you use to get the number of elements in a dictionary?
a. size
b. length
c. len
d. sizeof
8. 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
9. 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
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}
This will not be on the test...
11. What symbol is used as the dictionary merge operator?
a. +
b. :=
c. |
d. @=
12. What symbol is used as the dictionary update operator?
a. |
b. :=
c. |=
d. @=
This will not be on the test... 13. Which method can be used to add a group of elements to a set?
a. add
b. addgroup
c. update
d. addset
14. 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
This will not be on the final... 15. 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.
This will not be on the final... 16. 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.
We did not cover this, but it is good to know. Might be on final. 17. 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
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 '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'}
19. 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'}
20. 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. {'GA': 'Atlanta', 'FL': 'Tallahassee', 'NY': 'Albany', 'CA': 'San Diego'}
d. {'CA': 'San Diego', 'NY': 'Albany', 'GA': 'Atlanta'}
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 __________.