Copyright © 2014 Dr. James D. Palmer; This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License. Chapter 6 Collections

Copyright © 2014 Dr. James D. Palmer; This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License. Overview

Copyright © 2014 Dr. James D. Palmer; This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License. List Literal

Copyright © 2014 Dr. James D. Palmer; This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License. Lists Due to Python’s dynamic nature, lists may contain values of unrelated types or have unrelated purpose.

Copyright © 2014 Dr. James D. Palmer; This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License. Lists If you can’t describe a list as a collection of one kind of thing your program design likely has a problem.

Copyright © 2014 Dr. James D. Palmer; This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License. Common List Operations

Copyright © 2014 Dr. James D. Palmer; This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License. Common List Operations

Copyright © 2014 Dr. James D. Palmer; This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License. List Element Access Like strings, list elements are numbered sequentially starting at zero or using negative indexes from the end of the list. Using this convention we can access elements of a list much like we do for individual characters in a string.

Copyright © 2014 Dr. James D. Palmer; This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License. List Element Access

Copyright © 2014 Dr. James D. Palmer; This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License. List Slicing

Copyright © 2014 Dr. James D. Palmer; This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License. Changing Contents of a List

Copyright © 2014 Dr. James D. Palmer; This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License. Lists are Mutable

Copyright © 2014 Dr. James D. Palmer; This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License. Splitting Strings By default split uses whitespace to divide the substrings but different separators can be passed as an argument. One really useful way of generating a list is by splitting a string into substrings. This is accomplished using the string split method.

Copyright © 2014 Dr. James D. Palmer; This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License. Lists of Lists

Copyright © 2014 Dr. James D. Palmer; This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License. Lists of Lists

Copyright © 2014 Dr. James D. Palmer; This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License. Multi-Dimensional Lists Accessing individual elements of the matrix uses standard list notation but beware that the outer list represents the row and the inner list represents the column.

Copyright © 2014 Dr. James D. Palmer; This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License. Multi-Dimensional Lists If we changed the numbers in the matrix to X's and O's we could represent a Tic-Tac- Toe board.

Copyright © 2014 Dr. James D. Palmer; This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License. Dictionaries

Copyright © 2014 Dr. James D. Palmer; This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License. Dictionaries

Copyright © 2014 Dr. James D. Palmer; This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License. Dictionaries

Copyright © 2014 Dr. James D. Palmer; This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License. Dictionaries

Copyright © 2014 Dr. James D. Palmer; This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License. Dictionaries

Copyright © 2014 Dr. James D. Palmer; This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License. Dictionary Operations

Copyright © 2014 Dr. James D. Palmer; This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License. Dictionary Operations

Copyright © 2014 Dr. James D. Palmer; This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License. Tuple Literal

Copyright © 2014 Dr. James D. Palmer; This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License. Tuples Tuples are formed like lists but using parenthesis instead of brackets: A single element tuple must have a trailing comma:

Copyright © 2014 Dr. James D. Palmer; This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License. Tuple Operations

Copyright © 2014 Dr. James D. Palmer; This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License. Tuples Python also has some syntactic shorthand for tuples such that commas outside of a list or dictionary also define a tuple.

Copyright © 2014 Dr. James D. Palmer; This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License. Tuple Unpacking