Canvas

Canvas is the LMS (Learning Management System) that you are using right now to view this course. For questions about Canvas, check this list of help topics.

Repl.it

Repl.it is the tool that was used to create the interactive exercises in the lessons. The exercises are embedded in the lesson pages in Canvas, but you will need to be logged into Repl.it in order to view them.

The first time you view an Exploration page, you might see Captchas on all of the Repls. These are a security device which try to determine whether you are a human or robot by giving you a small puzzle that relies on human reasoning skills like abstraction. The most common is a grid of images and a prompt such as "Click on all images which contain a truck". You can get rid of these by solving the Captchas or "forking" the Repls. Possibly the fastest way to do this is to open each one (clicking on the "open in Replit" button in the top right and then ctrl+clicking on it again will open it in a new tab) and click on "fork" in the Replit site. Then you'll have your very own copy of the Repl in your Replit account, and if you refresh the Exploration page then you can edit your forked versions in the Canvas page.

GradeScope

At the bottom of each assignment page is a link to Gradescope, which will open in a new tab. On Gradescope you'll be able to click a link to submit your projects from GitHub.

Ed Discussion

There is a link to Ed Discussion in the left sidebar of Canvas. This ongoing Q&A forum is a valuable resource for getting official answers to your questions (and often helpful student responses also). It's good to use the search box before posting, to see if your question has already been addressed.

Teams

There is a link to Teams in the left sidebar of Canvas. This forum is for more informal interaction with your fellow students. It is also where TAs and instructors will hold office hours. You can add yourself to Teams by following the instructions here.

PyCharm

PyCharm is the IDE (Integrated Development Environment) that you will use in this course to develop your assignments. There are a few steps you'll need to follow to get PyCharm set up on your computer:

1. Download and install the current version of Python 3, found here.
2. Download and install the Community edition of PyCharm, found here.
3. Run PyCharm and answer the setup questions (accept the default if you aren't sure). You should reach the welcome screen, which looks like this (except you won't have any projects yet):
    
4. On the welcome screen, click on "New Project". You should now see this screen (your Python interpreter may not match yet):
   
5. In the "Location" path, replace "pythonProject" with "greeting". This will be the name of your project.
6. Uncheck "Create a main.py welcome script".
7. Next click on the little arrow to the left of "Python Interpreter". You should now see something like this:
    
8. Click on "Previously configured interpreter" and select whatever version of Python 3 you installed (make sure to select the interpreter you installed, not the installer file). PyCharm will remember this choice as the default for future projects (which is good, since Python 3 is what we'll use throughout the course). [If the Python 3 interpreter you installed doesn't appear, open the Settings/Preferences dialog, select Python Interpreter, click the icon and select Add.  Next select System Interpreter and then select your installation of Python 3.]  Next click "Create". You should now see this screen:
   
9. Near the top of the left pane, right-click on the project folder ("greeting"), select "New/Python File", and name the new file "greeting.py". In your new document, type the following: print("Hello world.")
10. Right-click anywhere on the document and select "Run 'greeting'" (which has a little green triangle icon to its left). This should make "Hello world." print to the output window. Congratulations - you've just created and run a program in Python!
11. Click on "Python Console" at the bottom left of your screen. This changes the bottom window from an output window to a console window, where you can use Python commands interactively. Try entering in this window the same print command that you put in your program. Interactive mode is handy for trying out simple things quickly, but for more complex things it's easier to write a program (or "script" as they're often called in interpreted languages such as Python). If you run your program again, the bottom window will switch back to showing the output of your program.

These instructions showed you how to create a project in PyCharm from scratch, however for the assignments in this course, you'll be creating projects in PyCharm from cloned GitHub repositories. That process will be explained below.

GitHub

GitHub is a popular web hosting service for Git repositories. Git is a distributed version control system that makes it easy to keep backups of different versions of your code and track changes that are made to it. You'll be using GitHub to host your assignment code. The assignment page in Canvas will contain a GitHub invitation link for each coding project. When you accept that invitation, GitHub will create a repository for you for that project. Your project's repository contains all of your project's files and stores each file's revision history. You can clone these repositories and then commit and push updates to them from within PyCharm. Cloning a repository creates a local copy of it. Committing a change updates your local copy. Pushing a change updates your repository on GitHub.

Install Git:

1. Download and install Git.
2. In the Settings/Preferences dialog of PyCharm, select Version Control | Git in the left pane and specify the path to the Git executable.

Use PyCharm to clone your repository from GitHub:

1. From the welcome screen, choose Get from VCS (you can always get back to the welcome screen by closing your project window). You should now see a dialog that has "Git" selected for "Version control", and has an empty field for URL, which is where you will copy the assignment repository URL that GitHub gives you (when you click on a project link from the Assignment pages). When you do that, the directory field will be filled in automatically. Then click on "Clone".
2. The first time you do this, you'll get a dialog that says "Log in to GitHub". Click on "Use Token...", and in the next dialog, click the "Generate..." button next to the Token field.  This will take you to a "New personal access token" page. You don't need to change any settings - just scroll down and click "Generate token". You should now see a page with your personal access token, which you will copy-paste into the "Token" field of the dialog. Now click "Log in".
3. You should now be in a new PyCharm project based on the sources you cloned from GitHub. Now you can read the specifications in the readme file, add a new file to the project with the specified name, and get coding! When you add new files to the project, PyCharm will ask if you want to add the file to Git, which you do, so you'll click "Add". This allows you to backup that file using Git and GitHub.

Use PyCharm to commit and push changes:

1. To commit and push changes to GitHub, click on the toolbar (in the upper right). This will bring up the Commit Changes dialog.
2. There should be a pane that shows the name of your .py file, with a checked box in front of it. This shows that that file will be included in the commit and push. There may be another box that says "Unversioned Files" next to it. This box should be unchecked, so that you aren't backing up a bunch of PyCharm project configuration files to your GitHub account.
3. There should be another pane titled "Commit Message". Enter a commit message. A good commit message should be a brief summary of what has changed since the last commit. You won't be graded on your commit messages, but if you need to roll back to a particular version of your code, good commit messages will help you find the one you're after. This will be especially important on the job, when working on large projects with many people.
4. From the Commit drop-down selection (in the lower right) choose "Commit and Push".  Then in the pane that pops up, confirm the Push.  Make sure that you commit and push.  If you just commit, that will only update your local copy of the repository, not the copy on GitHub.  The push is what updates the copy on GitHub.

(optional) Calling scripts from the interactive Python console in PyCharm

In the interactive exercises in the exploration pages, it's possible to call parts of a Python program (sometimes called a "script") directly from the interactive console.  However in PyCharm the default settings don't allow you to do this.  You don't need to be able to do that for this course, but if you would like to replicate that behavior in PyCharm, here's how.

In PyCharm, go to Run > Edit Configurations... > Check "Run with Python Console":

Now you should be able to call parts of a Python program from the interactive Python console in PyCharm.  One possible use of this is to write the program for your assignment and instead of writing test code in the same file (which you would need to delete before submitting), you could test the program by calling your code from the interactive console.