9. Glossary

A collection of key-value pairs that maps from keys to values. The keys can be any immutable type, and the values can be any type.
A built-in Python function that enables us to iterate over a collection and generate an auto-incremented index to associate with each item.
A data item that is mapped to a value in a dictionary. Keys are used to look up values in a dictionary.
key-value pair
One of the pairs of items in a dictionary. Values are looked up in a dictionary by key.
mapping type
A mapping type is a data type comprised of a collection of keys and associated values. Python’s only built-in mapping type is the dictionary. Dictionaries implement the associative array abstract data type.
A sequential collection of items, similar to a list. Any python object can be an element of a tuple. However, unlike a list, tuples are immutable.