Writing our First Programs

CS 110

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How to login to PollEverywhere!

On your phone / tablet, either scan the QR code here (or up on the screen) or go to pollev.com/baincs110

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Step 1. CLICK LOGIN

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Step 2. USE @U.NORTHWESTERN EMAIL ADDRESS

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Step 3. CLICK LOGIN WITH NORTHWESTERN

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Step 4. Follow sign-in steps with MFA

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Step 5. You may need to go back to pollev.com/baincs110 after you've setup your account. Make sure to set your NetID as your Screen Name!!!

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Announcements

• Sign into PollEverywhere to complete MQ0
• If you’re watching the recording, you’ll need to complete the Canvas version of MQ 0
• If you’re in class you’ll see your grade updated on Canvas by the end of the day.
• Exercise 0 is due this evening! We'll complete activities 2 - 4 in-class but don't forget to fill out the Google Form in Activity 0.
• Prof. Bain will have Office Hours today in TCH L370 until about 12:15pm in case you need help installing Python (part of Activity 1).

Next Week

• Monday - Operators and Variables in Python
• Wednesday - Functions in Python (Pre-Recorded - Out-of-Class MQ 1) + Tutorial 1
• Friday - Writing our Own Functions + MQ 2
• Exercise 1 - Due at 11:59pm on Canvas

A typical week…

Monday - Attend lecture, take a look at tutorial, and homework

Tuesday - Watch the pre-recorded lecture for Wednesday; peruse the tutorial

Wednesday - Come to the tutorial session, try your best to iron out all of your questions; see if you can do any of the HW

Thursday - by now, you should have a strong sense of how long it will take you to complete HW Exercise; if you need more time, apply for late penalty waiver

Friday - come to class, participate in activities; finish up HW

Sat/Sun - take the weekend off

Resources available throughout the week: Canvas, Class, Office Hours, and edSTEM

Turtle activities!

On our course web page

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Understanding the Words / Atoms of Programming

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Python is made up of different kinds of “words”, which can be used to construct sentences and paragraphs (statements and code blocks). Some types of ‘words’ in Python include:

• pieces of data like numbers, words, images, etc.
• operators are symbols that perform actions
• variables are containers that can hold data
• functions are blocks of code encased inside a function name
• reserved words (special words in python)
• modules

The first rule of programming!

Python will only do something you ask it to.

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Arithmetic Operators

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Variables

Named containers that allow us to store and access data in Python.

Variables

• Variables are named containers for storing and/or referencing data
• You assign values to variables using the assignment operator (equal sign)

variable_name = piece_of_data

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Variables

Turn the following statement into a sentence:

�favorite_cookie = "oreo"�

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Variables

Turn the following statement into a sentence:

�favorite_cookie = "oreo"�

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Variables

Turn the following statement into a sentence:

�favorite_cookie = "oreo"�

Assign the text "oreo" to a container called favorite_cookie.

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Variables

Turn the following statement into a sentence:

�favorite_cookie = "oreo"�

Assign the text "oreo" to a container called favorite_cookie.

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Big Idea: Our goal for any line of Python we write is to be able to explain what it does in plain english.

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Naming Variables

• Variable names in Python can be any length and can consist of:
• uppercase and lowercase letters (A-Z, a-z)
• digits (0-9)
• and the underscore character (_).
• The first character of a variable name cannot be a digit.

Example 1:

favorite_cookie = "oreo"

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Example 2:

1st_cookie = "oreo"

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Reminders

• For MQ0
• If you’re watching the recording, you’ll need to complete the Canvas version of MQ 0
• If you’re in class you’ll see your grade updated on Canvas by the end of the day (as long as you used your NetID as your screen name) - you don’t need to do the Canvas version
• Exercise 0 is due this evening! We'll complete activities 2 - 4 in-class but don't forget to fill out the Google Form in Activity 0.
• Prof. Bain will have Office Hours today in TCH L370 until about 12:15pm in case you need help installing Python (part of Activity 1).

Next Week

• Monday - Operators and Variables in Python
• Wednesday - Functions in Python (Pre-Recorded - Out-of-Class MQ 1) + Tutorial 1
• Friday - Writing our Own Functions + MQ 2
• Exercise 1 - Due at 11:59pm on Canvas