(3) Setting Up VS Code

In this document I’ll explain what a coding text editor is, why you need one, and how to set up VS Code as a text editor.

Jungeun Seo made some video walkthroughs for tutorials 1 - 3. You can find them in Tutorial Videos folder on the Google Drive. You’re not required to watch them, but you may find them helpful in combination with the written instructions.

Don’t Use A Word Processor for Coding

When programming, it is essential that you use a text editor, not a word processor. The following are examples of word processors, meaning they are not suitable for programming:

• Microsoft Word
• Apple Pages
• Google Docs
• OpenOffice Writer
• LibreOffice Writer

If you want to know why a word processor is bad for programming, read the optional section at the end of this document.

Installing Visual Studio Code

An integrated development environment (IDE) is software that includes a special text editor and other tools for programming. Visual Studio Code (VS Code) is an IDE. It has many features that we’ll set up in a later tutorial. For now, we’ll just use its text editor feature.

Visit https://code.visualstudio.com/download in a new tab. You should see a big blue rectangular button to download VS Code for your operating system (e.g., Windows or Mac). Click it. (Don’t use the small blue buttons unless you know what you’re doing.)

Expand the correct box below according to your operating system.

Opening VS Code and the EECS_183 Folder

Open VS Code by double-clicking its icon on your desktop. Choose File, Open folder, and navigate to your EECS_183 folder inside your Documents folder. Click on the EECS_183 folder to select it, and then click the Open or Select Folder button to open that folder in VS Code.

You should then see something like this on the left (though your icons may be a little different - that’s ok):

In particular, note that the EXPLORER area shows the contents of your EECS_183 folder.

Installing Needed Extensions

In VS Code, extensions are tools that we can add to make it do something special for us, like give us hints about possible problems in our Python code. At this time, you should see a little window pop up in the lower-right corner of VS Code, asking you to install some recommended extensions:

Click the Install button. When you’re asked to trust the publishers of certain extensions, click Trust Publishers & Install.

Setting Up VS Code for Running Python Programs

Python runs via something called an interpreter. This is just a special program that knows how to read and execute Python code. There’s an interpreter that comes with the Python installation on your computer, but we want to set up VS Code to use a special virtual environment interpreter. In Python, a virtual environment is a clean slate where we can install special tools without affecting the main Python installation on your computer. It’s kind of like a private toolbox (the virtual environment) inside of a garage full of tools (your computer). We can gather whatever special tools we need and put them inside, to be used only when we open up that toolbox. Whatever we put in the toolbox won’t clutter up the rest of the garage or get mixed up with other tools outside of the toolbox. This helps avoid certain conflicts.

In the subsections below, we’ll set up VS Code to use a virtual environment. You should only need to do this once.

Opening a Python File (and Selecting the Python Interpreter If Necessary)

For the moment, let’s make sure that VS Code is using the main Python interpreter installed on your computer. To check this, we need to open a Python file in VS Code.

Look at the left side bar of VS Code. You should see icons arranged vertically like the image below. You may have other icons as well, or icons in a different order. That’s fine.

We need to make sure that the EXPLORER area is open. The EXPLORER icon looks like two papers on top of each other: . Do you see in the image above that the EXPLORER icon is brighter? When I took that screenshot, the EXPLORER area was open, so the icon is highlighted. If your EXPLORER icon is not highlighted, click on it to highlight it and thus open the EXPLORER area. You should then see something like this:

Also note that you can click the EXPLORER icon repeatedly to show/hide the EXPLORER area.

Double click on setup.py in the EXPLORER area of VS Code. You should see setup.py open in VS Code. You don’t have to understand the text in this file. You should see something like this:

When you have a Python file (like setup.py) open, VS Code will usually automatically detect the Python interpreter installed on your computer. You can check that this is the case by looking in the lower-right corner of VS Code. You may see text indicating the version of your Python interpreter. For example, I see Python 3.14.2 (64-bit) in the lower-right corner of VS Code. Your version number should be 3.14.something. If it’s less, expand the special note below.

Running setup.py to Create a Virtual Environment

Next, we’ll make a single virtual environment to be used for this entire course, with a traditional name: .venv. We can do this by running the setup.py file. Open it in VS Code if you haven’t already. With setup.py open in VS Code, with you looking at the text, look for the right-pointing triangle in the upper-right corner of VS Code. It’s like a “play” button, as shown in the upper-right of the image below:

Hit that button to run setup.py.

Running setup.py may take several minutes. Eventually, you should see the output below in the TERMINAL area at the bottom of VS Code:

When it’s done, close VS Code by hitting the X in the top-right corner. Then open it again and open your EECS_183 folder in VS Code.

File ...\.venv\Scripts\Activate.ps1 cannot be loaded because running scripts 
is disabled on this system. For more information, see about_Execution_Policies 
at https:/go.microsoft.com/fwlink/?LinkID=135170.
    + CategoryInfo          : SecurityError: (:) [], PSSecurityException
    + FullyQualifiedErrorId : UnauthorizedAccess

Selecting the Python Interpreter (with a venv)

Our virtual environment is hopefully set up now. Let’s check. Look in the bottom-right corner of VS Code again. Instead of something like Python 3.14.2 (64-bit), you should now see something like Python 3.14.2 (.venv) or perhaps .venv (3.14.2) – and again, your version number may be different but should be 3.14.something. (You’ll likely also see the .venv folder in the EXPLORER area in the top left, but I’m not talking about that here.) If you don’t see the .venv text in the bottom right, make sure you expand the box directly below; for Mac users in particular, the steps in the expanded box directly below will likely be necessary.

Verifying the Virtual Environment is Set Up Correctly

Let’s verify further that the virtual environment is set up correctly. In the EXPLORER section in the upper-left, find the test_env.py file – it’s in the base EECS_183 folder. Double-click test_env.py to open it in VS Code. Again, you don’t have to understand what this code is doing. With the test_env.py file open in VS Code, with you looking at the text in the file, hit the right-pointing triangle in the upper-right corner of VS Code to run it. The script may take up to 30 seconds or so to run, but eventually you should see output like the following:

Checking Python environment... (Python 3.14.0)
[OK]   Virtual Environment Active (C:\Users\Steve\Documents\EECS_183\.venv)
------------------------------------------------------------
[OK]    numpy                2.3.5
[OK]    pandas               2.3.3
[OK]    matplotlib           3.10.8
[OK]    seaborn              0.13.2
[OK]    scikit-learn         1.8.0
[OK]    jupyterlab           4.5.1
[OK]    imageio              2.37.2
[OK]    flake8               7.3.0
[OK]    pep8-naming          0.15.1
[OK]    flake8-bugbear       25.11.29
------------------------------------------------------------

SUCCESS! Your environment is ready for class.

It’s ok if your version numbers are different from those shown above.

Turning On Auto Save

I recommend you turn on Auto Save, so that your edits are automatically saved periodically. Open the File menu. Find the Auto Save option. If the Auto Save option does not already have a check next to it, click it to add a check. It should then look like as shown below:

Making a New Python File in VS Code

Open your EECS_183 folder in VS Code if you don’t already have it open. Right-click (Windows) or control-click (Mac) on practice_code and choose New File. Name the file hello_again.py and then hit enter (Windows) or return (Mac). The .py means that the file we’re making is a Python code file.

Next, open hello_again.py by double-clicking on it in the EXPLORER area. You should see a blank file open. Paste in the following code:

print("Hello again!")

Save the file (File menu, Save, or note the shortcut key combination shown there). Click the right-pointing triangle in the upper-right corner of VS Code to run your program. You should see the output below in the TERMINAL area at the bottom of VS Code:

Hello again!

You just wrote your first Python program!

Finding Your Files From VS Code

Suppose you’re looking at a file in VS Code, and you’d like to open the File Explorer (Windows) or Finder (Mac) in the folder where that file exists. Here’s how to do that:

1. Look in the Explorer area in the top left corner of VS Code. If you don’t see it, tap the icon in the upper-left area first.
2. Find the file there that you’re interested in.

3. Follow the next step according to your operating system:

   • Windows: Right-click on the file and choose Reveal in File Explorer:
   • Mac: Control-click on the file and choose Reveal in Finder:
4. The File Explorer (Windows) or Finder (Mac) program should open in the folder in which that file exists.

Why Not Use a Word Processor? (Optional Reading)

Let’s start with some vocabulary:

• A character is a single symbol, like a letter, or a number, or %, @, etc.
• The ASCII characters are basically the characters you see on a U.S. computer keyboard. ASCII stands for American Standard Code for Information Interchange, and is pronounced “ASK-ee”.
• A plain text file is a file that contains only ASCII characters (and possibly others that we won’t worry about).
• Unlike a word processor, a text editor works only with plain text files.

You probably have a text editor on your computer already. For Macs, it’s called TextEdit. For Windows computers, it’s called Notepad. But these text editors are not designed specifically for programming, so the instructions above help you get Visual Studio Code installed.

Programs like Microsoft Word, Apple Pages, Google Docs, OpenOffice Writer, and LibreOffice Writer are not text editors; rather, they are word processors. A word processor can open a plain text file, but also works with specially-formatted documents.

Why is this distinction important? Consider the following bit of Python code, which we’ll call version A:

print("Hello world!")

Version A is how the code would appear if I typed it in a text editor. If I run a Python program containing only the command above, then the message Hello world! will be printed. (More on this in class!)

Suppose that instead of using a plain text editor, I typed my code in a word processor like Google Docs or Microsoft Word. In that case, I’d get what we’ll call version B:

print("Hello world!")

Would it surprise you to know that version B is not valid Python code? What’s the difference? Version A uses what are called straight quotes, or dumb quotes, while version B uses smart quotes. Most word processors will automatically make the smart quotes appear, knowing to curve the starting quotes differently from the ending quotes. It looks nice in English, but it’s not valid Python code. Python requires that I use straight quotes. So if I’m trying to type code in a word processor that automatically adds smart quotes, it’d get very annoying. I’d have to regularly go back and fix it. There are a few other examples like this that make word processors particularly problematic for coding.

Copyright and Academic Integrity

© 2026 Steven Bogaerts.

Materials for this assignment were developed with assistance from course staff, including Jungeun Seo.

This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

All materials provided for this course, including but not limited to labs, projects, notes, and starter code, are the copyrighted intellectual property of the author(s) listed in the copyright notice above. While these materials are licensed for public non-commercial use, this license does not grant you permission to post or republish your solutions to these assignments.

It is strictly prohibited to post, share, or otherwise distribute solution code (in part or in full) in any manner or on any platform, public or private, where it may be accessed by anyone other than the course staff. This includes, but is not limited to:

• Public-facing websites (like a personal blog or public GitHub repo).
• Solution-sharing websites (like Chegg or Course Hero).
• Private collections, archives, or repositories (such as student group “test banks,” club wikis, or shared Google Drives).
• Group messaging platforms (like Discord or Slack).

To do so is a violation of the university’s academic integrity policy and will be treated as such.

Asking questions by posting small code snippets to our private course discussion forum is not a violation of this policy.