Python-datastructures

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"In computer science, a data structure is a data organization, management, and storage format that enables efficient access and modification. More precisely, a data structure is a collection of data values, the relationships among them, and the functions or operations that can be applied to the data."

-- source: Wikipedia


Python knows how to work with of several types of data structures without the need to import additional libraries. Sometimes you do need to import a library to provide support (e.g. json, csv, sql) but most of these are already available when you have python installed. In rare cases you may need to build or acquire a third-party library for data structure support.


In these pages we mainly look at the most common data structures in python:


Name Examples Details Characteristic
Tuple ('January', 'February', 'March', 'April', 'May')

(2, 3, 5, 7, 11, 13, 17, 19, 23, 29)

Once set, values cannot be changed

Referenced with index

surrounded by one single open and closed parenthesis

elements separated by a comma

Strings are enclosed by apostrophes or quotes

List [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14]

['red', 'green', 'orange', 'blue']

Values can be modified, added, deleted

Referenced with index

surrounded by one single open and closed square bracket

elements separated by a comma

Strings are enclosed by apostrophes or quotes

Dictionary {'Joe':02079343, 'Alice':010534045, 'Bob':01084523}

{'x':234, 'y':345, 'z':456}

Values can be modified, added, deleted

Referenced with a key

surrounded by one single open and closed curly brace

elements separated by a comma

each element contains one key and one value

key and value are separated by a colon

key maybe a string or a number

strings (key or value) are enclosed by quotes

keys must be unique

Set ([1029, 1238, 7821, 4312, 2716]) Once set, values cannot be modified

Set values can be added and removed

Set may only contain unique values

Unordered

single square brackets surrounded by single parenthesis

elements separated by a comma

strings are enclosed by apostrophes or quotes

json [{ "first": "Joe', "hobbies": "swimming, running" }

{ "first": "Carol', "hobbies": "cycling, climbing" }]

Values can be modified, added, deleted

Referenced with a key

surrounded by one single open and closed curly brace (1x record)

multiple records surrounded by one single square open and close bracket

records surrounded by curly braces

record elements separated by a comma

each element contains one key and one value

key and value are separated by a colon

keys surrounded by double quotes

strings are enclosed by apostrophes or quotes

csv silver,32423,joe bloggs,"8,5",023-32425634,,,type=1,f once set, values cannot be modified elements separated by a comma

one record per line

elements enclosed by quotes if string contains a comma