Dictionary

Question 1

Definition of dictionary

Answer 1

A dictionary consists of keys and values. It is helpful to compare a dictionary to a list. Instead of the numerical indexes such as a list, dictionaries have keys. These keys are the keys that are used to access values within a dictionary

Question 2

Sample dictionary

Answer 2

In summary, like a list, a dictionary holds a sequence of elements. Each element is represented by a key and its corresponding value. Dictionaries are created with two curly braces containing keys and values separated by a colon. For every key, there can only be one single value, however, multiple keys can hold the same value. Keys can only be strings, numbers, or tuples, but values can be any data type.

release_year_dict = {“Thriller”: “1982”, “Back in Black”: “1980”, \
“The Dark Side of the Moon”: “1973”, “The Bodyguard”: “1992”, \
“Bat Out of Hell”: “1977”, “Their Greatest Hits (1971-1975)”: “1976”, \
“Saturday Night Fever”: “1977”, “Rumours”: “1977”}
release_year_dict

Answer:
{'Thriller': '1982',
 'Back in Black': '1980',
 'The Dark Side of the Moon': '1973',
 'The Bodyguard': '1992',
 'Bat Out of Hell': '1977',
 'Their Greatest Hits (1971-1975)': '1976',
 'Saturday Night Fever': '1977',
 'Rumours': '1977'}

Question 3

Retrieve all the keys

Answer 3

release_year_dict.keys( )

dict_keys([‘Thriller’, ‘Back in Black’, ‘The Dark Side of the Moon’, ‘The Bodyguard’, ‘Bat Out of Hell’, ‘Their Greatest Hits (1971-1975)’, ‘Saturday Night Fever’, ‘Rumours’])

Question 4

Retrieve all the values

Answer 4

release_year_dict.values( )

dict_values([‘1982’, ‘1980’, ‘1973’, ‘1992’, ‘1977’, ‘1976’, ‘1977’, ‘1977’])

Question 5

Add an entry

Answer 5

release_year_dict['Graduation'] = '2007'
release_year_dict
{'Thriller': '1982',
 'Back in Black': '1980',
 'The Dark Side of the Moon': '1973',
 'The Bodyguard': '1992',
 'Bat Out of Hell': '1977',
 'Their Greatest Hits (1971-1975)': '1976',
 'Saturday Night Fever': '1977',
 'Rumours': '1977',
 'Graduation': '2007'}