a) {1: ‘a’, 2: ‘b’} and c) {(1,2): ‘a’}<\/div>\n\t
Explanation:<\/h3>\n\t Dictionary keys must be of a type that is immutable. Tuples are immutable so they can be used as keys, unlike lists.<\/p>\n<\/div>\n\n
4. How can you add a new key-value pair to an existing dictionary d?<\/h2>\na) d.append(‘key’, ‘value’)<\/div>\n
b) d(‘key’) = ‘value’<\/div>\n
c) d[‘key’] = ‘value’<\/div>\n
d) d.add(‘key’ = ‘value’)<\/div>\n
Click to View Answer and Explanation<\/button>\n\n\t
Answer:<\/h3>\t\n\tc) d[‘key’] = ‘value’<\/div>\n\t
Explanation:<\/h3>\n\t New key-value pairs can be added to dictionaries using the assignment operator.<\/p>\n<\/div>\n\n
5. How can you remove a key-value pair from a dictionary?<\/h2>\na) d.remove(‘key’)<\/div>\n
b) del d[‘key’]<\/div>\n
c) d.delete(‘key’)<\/div>\n
d) d.pop(‘key’)<\/div>\n
Click to View Answer and Explanation<\/button>\n\n\t
Answer:<\/h3>\t\n\tb) del d[‘key’] and d) d.pop(‘key’)<\/div>\n\t
Explanation:<\/h3>\n\t Both del and the pop() method can be used to remove key-value pairs from dictionaries.<\/p>\n<\/div>\n\n
6. What method would you use to get the value of a key if it exists, otherwise return a default value?<\/h2>\na) d[‘key’] or ‘default’<\/div>\n
b) d.get(‘key’, ‘default’)<\/div>\n
c) d.value(‘key’, ‘default’)<\/div>\n
d) d.key(‘key’, ‘default’)<\/div>\n
Click to View Answer and Explanation<\/button>\n\n\t
Answer:<\/h3>\t\n\tb) d.get(‘key’, ‘default’)<\/div>\n\t
Explanation:<\/h3>\n\t <\/p>\n<\/div>\n\n
7. Which of the following is not true about dictionary keys?<\/h2>\na) They must be unique.<\/div>\n
b) They are immutable.<\/div>\n
c) They can be changed after creation.<\/div>\n
d) They can be numbers or strings.<\/div>\n
Click to View Answer and Explanation<\/button>\n\n\t
Answer:<\/h3>\t\n\tc) They can be changed after creation.<\/div>\n\t
Explanation:<\/h3>\n\t Dictionary keys must be of a type that is immutable, meaning they cannot be changed after creation.<\/p>\n<\/div>\n\n
8. Which method would return a list of all the keys in a dictionary?<\/h2>\na) d.keys()<\/div>\n
b) d.values()<\/div>\n
c) d.items()<\/div>\n
d) d.list()<\/div>\n
Click to View Answer and Explanation<\/button>\n\n\t
Answer:<\/h3>\t\n\ta) d.keys()<\/div>\n\t
Explanation:<\/h3>\n\t The keys() method of a dictionary returns a list of all the keys.<\/p>\n<\/div>\n\n
9. What will be the output of {1: ‘a’, 2: ‘b’}.values()?<\/h2>\na) [1, 2]<\/div>\n
b) [a, b]<\/div>\n
c) (‘a’, ‘b’)<\/div>\n
d) [‘a’, ‘b’]<\/div>\n
Click to View Answer and Explanation<\/button>\n\n\t
Answer:<\/h3>\t\n\td) [‘a’, ‘b’]<\/div>\n\t
Explanation:<\/h3>\n\t The values() method of a dictionary returns a list of all the values.<\/p>\n<\/div>\n\n
10. Which method can be used to get all key-value pairs in a dictionary as tuples?<\/h2>\na) d.keys()<\/div>\n
b) d.values()<\/div>\n
c) d.items()<\/div>\n
d) d.all()<\/div>\n
Click to View Answer and Explanation<\/button>\n\n\t
Answer:<\/h3>\t\n\tc) d.items()<\/div>\n\t
Explanation:<\/h3>\n\t The items() method returns all key-value pairs in a dictionary as tuples.<\/p>\n<\/div>\n\n
11. If d = {1: ‘a’, 2: ‘b’}, what will d[3] return?<\/h2>\na) None<\/div>\n
b) ‘c’<\/div>\n
c) Error<\/div>\n
d) 0<\/div>\n
Click to View Answer and Explanation<\/button>\n\n\t
Answer:<\/h3>\t\n\tc) Error<\/div>\n\t
Explanation:<\/h3>\n\t Accessing a key that doesn’t exist in the dictionary will raise a KeyError.<\/p>\n<\/div>\n\n
12. Dictionaries in Python are:<\/h2>\na) Ordered since Python 3.7<\/div>\n
b) Unordered<\/div>\n
c) Sorted by default<\/div>\n
d) Only ordered if numbers are used as keys<\/div>\n
Click to View Answer and Explanation<\/button>\n\n\t
Answer:<\/h3>\t\n\ta) Ordered since Python 3.7<\/div>\n\t
Explanation:<\/h3>\n\t Starting from Python 3.7, dictionaries maintain the insertion order of their items.<\/p>\n<\/div>\n\n
13. What does d.setdefault(‘key’, ‘default’) do?<\/h2>\na) Always sets ‘key’ to ‘default’ value.<\/div>\n
b) Only sets ‘key’ to ‘default’ if ‘key’ doesn’t exist.<\/div>\n
c) Only sets ‘key’ to ‘default’ if ‘key’ exists.<\/div>\n
d) Checks if ‘default’ exists in ‘key’.<\/div>\n
Click to View Answer and Explanation<\/button>\n\n\t
Answer:<\/h3>\t\n\tb) Only sets ‘key’ to ‘default’ if ‘key’ doesn’t exist.<\/div>\n\t
Explanation:<\/h3>\n\t The setdefault() method returns the value of a key if it exists, otherwise inserts the key with a specified value.<\/p>\n<\/div>\n\n
14. Which method can be used to copy a dictionary?<\/h2>\na) d.copy()<\/div>\n
b) d.clone()<\/div>\n
c) dict(d)<\/div>\n
d) Both a and c<\/div>\n
Click to View Answer and Explanation<\/button>\n\n\t
Answer:<\/h3>\t\n\td) Both a and c<\/div>\n\t
Explanation:<\/h3>\n\t Both the copy() method and the dict() constructor can be used to create a shallow copy of a dictionary.<\/p>\n<\/div>\n\n
15. Which of the following will clear all entries from the dictionary d?<\/h2>\na) d.remove()<\/div>\n
b) d.delete()<\/div>\n
c) d = {}<\/div>\n
d) d.clear()<\/div>\n
Click to View Answer and Explanation<\/button>\n\n\t
Answer:<\/h3>\t\n\td) d.clear()<\/div>\n\t
Explanation:<\/h3>\n\t The clear() method removes all items from the dictionary.<\/p>\n<\/div>\n\n