Python Language Dictionary: Difference between revisions

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* [[Python_Language#Dictionary|Python Language]]
* [[Python_Language#Dictionary|Python Language]]
=Overview=
=Overview=
A dictionary is a mutable collection of key-value pairs. The pairs can be [[#Access_a_Dictionary|accessed]] and [[#Modify_a_Dictionary|modified]].
A dictionary is a mutable collection of key-value pairs. The pairs can be [[#Access_a_Dictionary|accessed]] and [[#Modify_a_Dictionary|modified]]. Each key is unique within the key set, and can be an instance of any immutable type: boolean, integer, float, tuple, string, etc. In other programming languages, the same data structure is referred to as "[[Bash_Arrays#Associative_Arrays|associative array]]" or "[[Hash_Table#Overview|hash tables]]" or "hash maps".


=Create a Dictionary=
=Create a Dictionary=

Revision as of 19:51, 16 February 2022

Internal

Overview

A dictionary is a mutable collection of key-value pairs. The pairs can be accessed and modified. Each key is unique within the key set, and can be an instance of any immutable type: boolean, integer, float, tuple, string, etc. In other programming languages, the same data structure is referred to as "associative array" or "hash tables" or "hash maps".

Create a Dictionary

Empty map

m = {}

Access a Dictionary

Access Individual Elements

[], get()

An attempt to access an inexistent key ends up in a KeyError exception being thrown.

Test the existence of a key.

Access:

d["key"]

Get All Keys

Get All Values

Modify a Dictionary

Modify Individual Elements

Add, modify, delete.

Combine Dictionaries