Dictionaries – embodied in the dict
type – are completely fundamental to the
way the Python language works, and are very widely used. A dictionary maps keys
to values, and in some languages it is known as a map or associative array. Let's look at how to create and use dictionaries in Python.
Literal dictionaries are created using curly braces containing key-value pairs. Each pair is separated by a comma, and each key is separated from its corresponding value by a colon. Here we use a dictionary to create a simple telephone directory:
>>> d = {'alice': '878-8728-922', 'bob': '256-5262-124',
'eve': '198-2321-787'}
We can retrieve items by key using the square brackets operator:
>>> d['alice'] '878-8728-922'
And we can update the value associated with a particular key by assigning through the square brackets:
>>> d['alice'] = '966-4532-6272' >>> d {'bob': '256-5262-124', 'eve': '198-2321-787', 'alice': '966...