Difference between revisions of "EGR 103/Concept List Fall 2019"
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| Line 43: | Line 43: | ||
** a[2][3] is the same as a[2, 3] | ** a[2][3] is the same as a[2, 3] | ||
** Only works for arrays! | ** Only works for arrays! | ||
| + | == Lecture 4 - Other Types and Functions == | ||
| + | * Lists are set off with [ ] and entries can be any valid type (including other lists!); entries can be of different types from other entries | ||
| + | * List items can be changed | ||
| + | * Tuples are indicated by commas without square brackets (and are usually shown with parentheses - which are required if trying to make a tuple an entry in a tuple or a list) | ||
| + | * Dictionaries are collections of key : value pairs set off with { }; keys can be any immutable type (int, float, string, tuple) and must be unique; values can be any type and do not need to be unique | ||
| + | * To read more: | ||
| + | ** Note! Many of the tutorials below use Python 2 so instead of <code>print(thing)</code> it shows <code>print thing</code> | ||
| + | ** [https://www.tutorialspoint.com/python/python_lists.htm Lists] at tutorialspoint | ||
| + | ** [hhttps://www.tutorialspoint.com/python/python_tuples.htm Tuples] at tutorialspoint | ||
| + | ** [hhttps://www.tutorialspoint.com/python/python_dictionary.htm Dictionary] at tutorialspoint | ||
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Revision as of 21:11, 6 September 2019
This page will be used to keep track of the commands and major concepts for each lecture in EGR 103.
Contents
Lecture 1 - Introduction
- Class web page: EGR 103L; assignments, contact info, readings, etc - see slides on Errata/Notes page
- Sakai page: Sakai 103L page; grades, surveys and tests, some assignment submissions
- CampusWire page: CampusWire 103L page; message board for questions - you need to be in the class and have the access code to subscribe.
Lecture 2 - Programs and Programming
- Seven steps of programming -
- Watch video on Developing an Algorithm
- Watch video on A Seven Step Approach to Solving Programming Problems
- To play with Python:
- Install it on your machine or a public machine: Download
- Quick tour of Python
- Editing window, variable explorer, and console
- You are not expected to remember any of the specifics about how Python stores things or works with them yet!
Lecture 3 - "Number" Types
- Python is a "typed" language - variables have types
- We will use eight types:
- Focus of the day: int, float, and array
- Focus a little later: string, list, tuple
- Focus later: dictionary, set
- int: integers; Python can store these perfectly
- float: floating point numbers - "numbers with decimal points" - Python sometimes has problems
- array
- Requires numpy, usually with
import numpy as np - Organizational unit for storing rectangular arrays of numbers
- Requires numpy, usually with
- Math with "Number" types works the way you expect
- ** * / // % + -
- Relational operators can compare "Number" Types and work the way you expect with True or False as an answer
- < <= == >= > !=
- With arrays, either same size or one is a single value; result will be an array of True and False the same size as the array
- Slices allow us to extract information from an array or put information into an array
- a[0] is the element in a at the start
- a[3] is the element in a three away from the start
- a[:] is all the elements in a because what is really happening is:
- a[start:until] where start is the first index and until is just *past* the last index;
- a[3:7] will return a[3] through a[6] in 4-element array
- a[start:until:increment] will skip indices by increment instead of 1
- To go backwards, a[start:until:-increment] will start at an index and then go backwards until getting at or just past until.
- For 2-D arrays, you can index items with either separate row and column indices or indices separated by commas:
- a[2][3] is the same as a[2, 3]
- Only works for arrays!
Lecture 4 - Other Types and Functions
- Lists are set off with [ ] and entries can be any valid type (including other lists!); entries can be of different types from other entries
- List items can be changed
- Tuples are indicated by commas without square brackets (and are usually shown with parentheses - which are required if trying to make a tuple an entry in a tuple or a list)
- Dictionaries are collections of key : value pairs set off with { }; keys can be any immutable type (int, float, string, tuple) and must be unique; values can be any type and do not need to be unique
- To read more:
- Note! Many of the tutorials below use Python 2 so instead of
print(thing)it showsprint thing - Lists at tutorialspoint
- [hhttps://www.tutorialspoint.com/python/python_tuples.htm Tuples] at tutorialspoint
- [hhttps://www.tutorialspoint.com/python/python_dictionary.htm Dictionary] at tutorialspoint
- Note! Many of the tutorials below use Python 2 so instead of
