What this page does
Introduces the four skills you will learn in this guide.
Where this fits
This is the starting point. No prior knowledge required.
Explanation
By the end of this guide, you will know how to:
- Use Mac Terminal — Navigate folders, run commands, manage files
- Install Python — Get the latest Python on your Mac using Homebrew
- Use pip — Install, list, and remove Python packages
- Use venv — Create isolated environments for each project
These are foundational skills. Every Python project you build will use them.
Why this matters
Without these skills, you cannot run Python projects. This guide ensures you have a solid foundation before writing any code.
⚠ If something breaks here
Nothing to break yet. Move to Page 2.
What this page does
Shows you how to open Terminal on your Mac.
Where this fits
This is your first action. Terminal is where you will run all commands.
Code (this page)
Press: Command + Space
Type: Terminal
Press: Enter
Explanation
Command + Space opens Spotlight Search. Type "Terminal" and press Enter to launch it.
Alternatively:
- Open Finder
- Go to Applications → Utilities → Terminal
Terminal is a text-based interface to your computer. Instead of clicking icons, you type commands.
Why this matters
Terminal is how developers interact with their computer. You will use it constantly.
⚠ If something breaks here
- If Spotlight doesn't open: Go to System Settings → Keyboard → Shortcuts → Spotlight
- If Terminal not found: Open Finder → Applications → Utilities → Terminal
What this page does
Explains what you see when Terminal opens.
Where this fits
You have Terminal open. Now understand what you're looking at.
Explanation
You will see something like:
username@MacBook-Pro ~ %
Breaking it down:
username — Your Mac usernameMacBook-Pro — Your computer name~ — Your current location (home folder)% — The prompt (Terminal is ready for input)
The blinking cursor after
% is where you type commands.
Why this matters
Understanding the prompt helps you know where you are and confirms Terminal is ready.
⚠ If something breaks here
- If you see
$ instead of %: That's fine, older Mac or different shell
- If no prompt appears: Close Terminal and reopen it
What this page does
Teaches your first Terminal command: pwd.
Where this fits
Terminal is open. Now run your first command.
Code (this page)
Explanation
Type pwd and press Enter.
pwd stands for "print working directory." It shows your current location in the file system.
You will see something like:
/Users/kevin
This is your home folder. All your files live somewhere inside this.
Why this matters
Knowing where you are is essential. Many commands depend on your current location.
⚠ If something breaks here
command not found: Make sure you typed pwd exactly (lowercase)- No output: Press Enter after typing the command
What this page does
Teaches the ls command to see folder contents.
Where this fits
You know where you are. Now see what's there.
Code (this page)
Explanation
Type ls and press Enter.
ls stands for "list." It shows all files and folders in your current location.
You will see something like:
Desktop Documents Downloads Movies Music Pictures
These are folders inside your home directory.
Why this matters
ls is how you explore. You will use it constantly to see what files exist.
⚠ If something breaks here
- Nothing listed: Your folder might be empty (unlikely for home folder)
command not found: Make sure you typed ls exactly (lowercase L, lowercase S)
What this page does
Teaches the cd command to move between folders.
Where this fits
You can see folders. Now move into one.
Code (this page)
Explanation
Type cd Desktop and press Enter.
cd stands for "change directory." It moves you into a folder.
Your prompt will change:
username@MacBook-Pro Desktop %
Now Desktop appears instead of ~. You are inside the Desktop folder.
Run pwd to confirm:
pwd
Output:
/Users/kevin/Desktop
Why this matters
Navigation is fundamental. You must be in the right folder to work with files.
⚠ If something breaks here
No such file or directory: Check spelling, capitalization matters- Use
ls first to see exact folder names
What this page does
Teaches how to move up one folder level.
Where this fits
You are in Desktop. Now go back to home.
Code (this page)
Explanation
Type cd .. and press Enter.
.. means "parent folder" — the folder containing your current folder.
Your prompt returns to:
username@MacBook-Pro ~ %
The ~ confirms you are back in your home folder.
Why this matters
You need to move both into folders and back out of them.
⚠ If something breaks here
- Still in Desktop: Make sure there's a space between
cd and ..
- Type
cd ~ to go directly home from anywhere
What this page does
Teaches how to create a new folder.
Where this fits
You can navigate. Now create folders for your projects.
Code (this page)
Explanation
Type mkdir projects and press Enter.
mkdir stands for "make directory." It creates a new folder.
Verify it exists:
ls
You will see projects in the list.
Why this matters
You will create folders for every project. This keeps your work organized.
⚠ If something breaks here
File exists: A folder named projects already exists (that's fine)Permission denied: You might be in a protected folder, run cd ~ first
What this page does
Teaches how to create an empty file.
Where this fits
You can create folders. Now create files inside them.
Code (this page)
cd projects
touch test.txt
Explanation
First, move into your projects folder with cd projects.
Then, touch test.txt creates an empty file named test.txt.
Verify:
ls
You will see test.txt listed.
Why this matters
Creating files from Terminal is faster than using Finder for quick tasks.
⚠ If something breaks here
- File not appearing: Make sure you're in the right folder (
pwd to check)
Permission denied: Check folder permissions
What this page does
Teaches how to delete a file.
Where this fits
You created a test file. Now remove it.
Code (this page)
Explanation
Type rm test.txt and press Enter.
rm stands for "remove." It deletes files permanently.
Warning: There is no trash. Deleted files are gone forever.
Verify:
ls
The file is gone.
Why this matters
Cleaning up test files keeps your projects tidy. But be careful — deletion is permanent.
⚠ If something breaks here
No such file: File already deleted or wrong name- To delete folders: Use
rm -r foldername (the -r means recursive)
What this page does
Teaches how to clean up your Terminal window.
Where this fits
Your Terminal is full of old commands. Clean it up.
Code (this page)
Explanation
Type clear and press Enter.
Your Terminal window becomes blank, with just a fresh prompt.
Keyboard shortcut: Command + K does the same thing.
Why this matters
A clean screen helps you focus. Use it often.
⚠ If something breaks here
Nothing can break here. If clear doesn't work, Command + K always will.
What this page does
Verifies you have learned the essential Terminal commands.
Where this fits
You have completed the Terminal section. Confirm your skills.
Explanation
You should now be able to:
| Command | Purpose |
pwd | Print current location |
ls | List folder contents |
cd folder | Move into a folder |
cd .. | Move up one level |
mkdir name | Create a folder |
touch name | Create a file |
rm name | Delete a file |
clear | Clean the screen |
Why this matters
These eight commands are the foundation. You will use them every day.
⚠ If something breaks here
Review pages 4-11 for any command you're unsure about.
What this page does
Checks whether Python is already on your Mac.
Where this fits
Terminal basics complete. Now check for Python.
Code (this page)
Explanation
Type python3 --version and press Enter.
If Python is installed, you will see:
Python 3.12.4
(Your version number may differ.)
If you see command not found, Python is not installed. That's fine — we will install it next.
Why this matters
Many Macs have Python pre-installed. Check before installing.
⚠ If something breaks here
command not found is expected if Python isn't installed- Continue to Page 14 to install Python
What this page does
Installs Homebrew, the Mac package manager.
Where this fits
Before installing Python, we need Homebrew.
Code (this page)
/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"
Explanation
Copy and paste this entire command into Terminal and press Enter.
Homebrew is a "package manager" — it installs software for you.
The installation will:
- Ask for your Mac password (type it, nothing will appear)
- Ask you to press Enter to confirm
- Take a few minutes to download and install
When done, you will see "Installation successful!"
Why this matters
Homebrew makes installing Python (and many other tools) easy and clean.
⚠ If something breaks here
- Password not accepted: Type carefully, it's your Mac login password
- Already installed: Message says "Homebrew is already installed" — that's fine
- Network error: Check your internet connection
What this page does
Installs the latest Python using Homebrew.
Where this fits
Homebrew is installed. Now use it to install Python.
Code (this page)
Explanation
Type brew install python and press Enter.
Homebrew will:
- Download Python
- Install it to the correct location
- Set up the
python3 and pip3 commands
This takes 1-2 minutes.
Why this matters
This installs the latest, properly configured Python on your Mac.
⚠ If something breaks here
brew: command not found: Homebrew didn't install correctly, redo Page 14- Already installed:
Warning: python is already installed — that's fine
What this page does
Confirms Python is installed correctly.
Where this fits
Python was installed. Now verify it works.
Code (this page)
Explanation
Run python3 --version again.
You should see:
Python 3.12.4
(Or a newer version.)
Also check pip:
pip3 --version
You should see:
pip 24.0 from /opt/homebrew/lib/python3.12/site-packages/pip (python 3.12)
Why this matters
Verification confirms everything is set up correctly before you continue.
⚠ If something breaks here
- Version not showing: Close Terminal, reopen, try again
- Wrong version: Run
brew upgrade python
What this page does
Explains why we use python3 instead of python.
Where this fits
Python is installed. Understand the naming convention.
Explanation
On Mac, there are often two Pythons:
| Command | Version |
python | Python 2 (old, deprecated) |
python3 | Python 3 (current, use this) |
Always use python3 and pip3 to ensure you're using the modern version.
You can check what python points to:
python --version
If it shows Python 2.x, that's the old system Python. Ignore it.
Why this matters
Using the wrong Python causes confusing errors. Always use python3.
⚠ If something breaks here
Nothing to break. This is informational.
What this page does
Shows how to start Python's interactive mode.
Where this fits
Python is verified. Now run it.
Code (this page)
Explanation
Type python3 and press Enter.
Your prompt changes:
>>>
This is the Python interpreter. You can type Python code directly:
>>> print("Hello, World!")
Hello, World!
>>> 2 + 2
4
Why this matters
The interactive mode is great for testing small pieces of code quickly.
⚠ If something breaks here
- No
>>> prompt: Make sure you typed python3 not python
- Syntax error: Python code must be exact, check spelling and quotes
What this page does
Shows how to exit the Python interpreter.
Where this fits
You are in Python's interactive mode. Now exit back to Terminal.
Code (this page)
Explanation
Type exit() and press Enter.
You return to the normal Terminal prompt:
username@MacBook-Pro ~ %
Alternative: Press Control + D to exit.
Why this matters
You need to switch between Python and Terminal. Know how to exit.
⚠ If something breaks here
- Still seeing
>>>: Type exit() with parentheses, not just exit
- Keyboard shortcut:
Control + D always works
What this page does
Verifies you have installed and can run Python.
Where this fits
You have completed the Python installation section.
Explanation
You should now be able to:
| Task | Command |
| Check Python version | python3 --version |
| Check pip version | pip3 --version |
| Start Python | python3 |
| Exit Python | exit() |
Why this matters
Python is installed and working. You can now install packages and run scripts.
⚠ If something breaks here
Review pages 13-19 for any step you missed.
What this page does
Explains what pip is and why you need it.
Where this fits
Python is installed. Now understand how to add functionality.
Explanation
pip stands for "Pip Installs Packages."
Python itself is basic. Pip lets you install packages — pre-written code that adds features:
| Package | What It Does |
requests | Make web requests |
pandas | Work with data tables |
pygame | Create games |
flask | Build websites |
Instead of writing everything from scratch, you install packages others have made.
Why this matters
Every real Python project uses packages. pip is how you get them.
⚠ If something breaks here
Nothing to break. This is informational.
What this page does
Confirms pip is working on your system.
Where this fits
You understand what pip is. Now verify it works.
Code (this page)
Explanation
Run pip3 --version in Terminal.
You should see something like:
pip 24.0 from /opt/homebrew/lib/python3.12/site-packages/pip (python 3.12)
This confirms:
- pip is installed
- Which Python it's connected to
- Where it's located
Why this matters
Verifying pip works before using it saves debugging time later.
⚠ If something breaks here
command not found: Run python3 -m pip --version instead- Old version: Run
pip3 install --upgrade pip
What this page does
Teaches how to install a Python package.
Where this fits
pip is verified. Now use it to install something.
Code (this page)
Explanation
Type pip3 install requests and press Enter.
pip will:
- Download the
requests package from the internet
- Install it on your system
- Show "Successfully installed requests-2.x.x"
requests is a popular package for making web requests. We're using it as an example.
Why this matters
This is how you add any package to Python. The syntax is always pip3 install packagename.
⚠ If something breaks here
Permission denied: You may need to use a virtual environment (covered soon)- Network error: Check your internet connection
What this page does
Shows how to see what packages are installed.
Where this fits
You installed a package. Now see all installed packages.
Code (this page)
Explanation
Type pip3 list and press Enter.
You will see a table:
```
Package Version
Why this matters
Knowing what's installed helps you manage your environment and debug issues.
⚠ If something breaks here
- Empty list: That's unusual, but pip itself should appear
- Long list: System Python may have many pre-installed packages
What this page does
Shows how to remove a package.
Where this fits
You can install and list packages. Now remove one.
Code (this page)
Explanation
Type pip3 uninstall requests and press Enter.
pip will ask: Proceed (Y/n)?
Type Y and press Enter to confirm.
You will see "Successfully uninstalled requests-2.x.x"
Why this matters
Sometimes you need to remove packages — to fix conflicts or clean up.
⚠ If something breaks here
Not installed: Package wasn't there (check spelling)- Re-install it:
pip3 install requests (we'll use it later)
What this page does
Explains the requirements.txt file.
Where this fits
You can install packages one at a time. But projects need many packages.
Explanation
A requirements.txt file lists all packages a project needs:
requests==2.31.0
pandas==2.0.3
numpy==1.24.3
Each line is a package name and version.
When you share your project, others can install everything with one command.
Why this matters
requirements.txt ensures everyone has the exact same packages. This prevents "it works on my machine" problems.
⚠ If something breaks here
Nothing to break. This is informational.
What this page does
Shows how to create a requirements.txt file.
Where this fits
You understand what requirements.txt is. Now create one.
Code (this page)
pip3 freeze > requirements.txt
Explanation
First, make sure you're in your projects folder:
cd ~/projects
Then run pip3 freeze > requirements.txt.
pip3 freeze lists all installed packages with versions> redirects output to a filerequirements.txt is the filename
View the file:
cat requirements.txt
Why this matters
This is how you document your project's dependencies for others (or yourself later).
⚠ If something breaks here
- Empty file: No packages installed (that's okay for now)
No such file or directory: Make sure you're in a folder you can write to
What this page does
Shows how to install all packages from requirements.txt.
Where this fits
You created a requirements.txt. Now use one.
Code (this page)
pip3 install -r requirements.txt
Explanation
The -r flag tells pip to read from a file.
pip will install every package listed in requirements.txt.
This is how you:
- Set up a project someone shared with you
- Restore your environment on a new computer
- Match a teammate's setup exactly
Why this matters
One command installs everything. No manual package-by-package installation.
⚠ If something breaks here
No such file: Make sure requirements.txt exists in current folder- Version conflicts: The file may have outdated versions
What this page does
Verifies you understand pip and package management.
Where this fits
You have completed the pip section.
Explanation
You should now be able to:
| Task | Command |
| Install a package | pip3 install packagename |
| List packages | pip3 list |
| Uninstall a package | pip3 uninstall packagename |
| Save dependencies | pip3 freeze > requirements.txt |
| Install from file | pip3 install -r requirements.txt |
Why this matters
Package management is essential for every Python project.
⚠ If something breaks here
Review pages 21-28 for any command you're unsure about.
What this page does
Explains why virtual environments exist.
Where this fits
You can install packages globally. But that causes problems.
Explanation
Problem: Different projects need different package versions.
- Project A needs
requests==2.25.0
- Project B needs
requests==2.31.0
If you install globally, one project breaks.
Solution: Virtual environments.
A venv is an isolated Python environment. Each project gets its own:
- Python interpreter
- Installed packages
- requirements.txt
Projects don't interfere with each other.
Why this matters
Professional Python development requires virtual environments. Always use them.
⚠ If something breaks here
Nothing to break. This is informational.
What this page does
Creates your first virtual environment.
Where this fits
You understand why venv matters. Now create one.
Code (this page)
cd ~/projects
mkdir my-first-project
cd my-first-project
python3 -m venv venv
Explanation
Step by step:
cd ~/projects — Go to your projects foldermkdir my-first-project — Create a project foldercd my-first-project — Enter the folderpython3 -m venv venv — Create a virtual environment
The
-m venv runs Python's venv module. The second
venv is the folder name (convention).
Check it was created:
ls
You should see a venv folder.
Why this matters
Every project should start with creating a venv.
⚠ If something breaks here
No module named venv: Run brew install python again- Permission denied: Check folder permissions
What this page does
Shows how to activate your virtual environment.
Where this fits
You created a venv. Now activate it.
Code (this page)
Explanation
Type source venv/bin/activate and press Enter.
Your prompt changes:
(venv) username@MacBook-Pro my-first-project %
The (venv) prefix means the virtual environment is active.
Now when you run pip3 install, packages go into this venv only.
Why this matters
You must activate the venv before working on a project. Otherwise packages install globally.
⚠ If something breaks here
No such file: Make sure you're in the folder containing venv- Wrong path: It's
venv/bin/activate not venv/activate
What this page does
Shows how to exit the virtual environment.
Where this fits
The venv is active. Now learn to deactivate it.
Code (this page)
Explanation
Type deactivate and press Enter.
Your prompt returns to normal:
username@MacBook-Pro my-first-project %
The (venv) prefix is gone. You are back to the global Python.
Why this matters
When switching projects, deactivate one venv before activating another.
⚠ If something breaks here
command not found: You weren't in an active venv- This command only works when a venv is active
What this page does
Summarizes the benefits of virtual environments.
Where this fits
You can create, activate, and deactivate venvs. Understand why.
Explanation
Always use venv because:
| Benefit | Explanation |
| Isolation | Project A's packages don't affect Project B |
| Reproducibility | requirements.txt captures exact versions |
| Clean uninstall | Delete the venv folder, everything's gone |
| No sudo | Install packages without admin rights |
| Version testing | Test different package versions easily |
Best practice: Create a venv as the first step for every new project.
Why this matters
Professional developers always use virtual environments. It's an industry standard.
⚠ If something breaks here
Nothing to break. This is informational.
What this page does
Verifies you can manage virtual environments.
Where this fits
You have completed the venv section.
Explanation
You should now be able to:
| Task | Command |
| Create a venv | python3 -m venv venv |
| Activate (Mac) | source venv/bin/activate |
| Deactivate | deactivate |
| Check if active | Look for (venv) in prompt |
Typical workflow:
mkdir new-project
cd new-project
python3 -m venv venv
source venv/bin/activate
pip3 install requests
pip3 freeze > requirements.txt
Why this matters
This workflow is the foundation of every Python project.
⚠ If something breaks here
Review pages 30-34 for any concept you're unsure about.
What this page does
Confirms you have mastered all skills in this guide.
Where this fits
This is the end. Verify everything works together.
Explanation
Complete this final test:
cd ~/projects
mkdir test-project
cd test-project
python3 -m venv venv
source venv/bin/activate
pip3 install requests
pip3 freeze > requirements.txt
cat requirements.txt
python3 -c "import requests; print('Success!')"
deactivate
If you see "Success!" — you have completed the guide.
You can now:
- Navigate with Terminal
- Install and run Python
- Manage packages with pip
- Isolate projects with venv
Why this matters
You are ready to build Python projects. This foundation supports everything you'll create.
⚠ If something breaks here
- Review the specific section where the error occurred
- Each skill builds on the previous one