Python Language Dictionary: Difference between revisions
Jump to navigation
Jump to search
| Line 6: | Line 6: | ||
=Create a Dictionary= | =Create a Dictionary= | ||
A new dictionary instance is declared using the <code>{</code></code>}</code> syntax. The dictionary can be empty | |||
<syntaxhighlight lang='python'> | <syntaxhighlight lang='python'> | ||
d = {} | |||
</syntaxhighlight> | |||
or it can be populated with values: | |||
<syntaxhighlight lang='python'> | |||
d = {'a':'b', 1:2, true:"this is true"} | |||
</syntaxhighlight> | </syntaxhighlight> | ||
Revision as of 19:54, 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
A new dictionary instance is declared using the {} syntax. The dictionary can be empty
d = {}
or it can be populated with values:
d = {'a':'b', 1:2, true:"this is true"}
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.