Mastering Python for Networking and Security

Dictionaries

The Python dictionary data structure allows us to associate values with keys. A key is any immutable object. The value associated with a key can be accessed with the indexing operator. In Python, dictionaries are implemented using hash tables.

A Python dictionary is a storage method for key:value pairs. Python dictionaries are enclosed in curly brackets, {}.Dictionaries, also called associative matrices, which owe their name to collections that relate a key and a value. For example, let's look at a dictionary of protocols with names and numbers:

>>> services = {"ftp":21, "ssh":22, "smtp":25, "http":80}

The limitation with dictionaries is that we cannot create multiple values with the same key. This will overwrite the previous ...