Python Dictionary MCQ

Dictionary Elements

• In a dictionary, all elements are separated by commas.
• Each element is a key-value pair, separated by a colon.

Dictionary Uniqueness

• In a dictionary, keys must be unique, but values can be duplicated.

Dictionary Example

• A dictionary is a data type that stores a collection of key-value pairs, such as D = {1 : “One”, 2 : “Two”, 3 : “Three”}.

Dictionary Keys

• In a dictionary, keys can be any immutable data type, such as integers, strings, or tuples.
• In the example D = {1 : “One”, 2 : “Two”, 3 : “Three”}, the keys are 1, 2, and 3.

Accessing Non-Existent Keys

• If you try to access a key that does not exist in a dictionary, a KeyError is raised.

Deleting Dictionary Elements

• The del statement or the pop() method can be used to delete an element from a dictionary.

Duplicate Values

• In a dictionary, duplicate values for keys are allowed, but each key must be unique.

Clearing a Dictionary

• The clear() method is used to remove all elements from a dictionary, leaving it empty.
• The result of running d = {1: 'one', 2: 'two', 3: 'three'}; d.clear(); print(d) is an empty dictionary {}.

Dictionary Data Type

• A dictionary is an unordered collection of items in Python.

Accessing Non-Existent Keys Error

• If you try to access a key that does not exist in a dictionary in Python, a KeyError is raised.