Navigating the Terminal

Before we run our Python script, let's learn a few basic terminal commands.

You don't need to become a Linux expert.

We only want to learn enough to move around our project files and run our programs.

Imagine your computer's files as a set of folders:

home/
└── student/
    ├── projects/
    │   ├── app.py
    │   └── notes.txt
    └── downloads/

The terminal lets us move through this structure.

Where am I?

Use:

pwd

pwd means Print Working Directory.

It tells you which folder you are currently inside.

For example:

/home/student/projects

Think of it as asking:

"Where am I right now?"

What is inside this folder?

Use:

ls

ls shows the files and folders in your current location.

For example:

app.py
notes.txt
projects

Think of it as:

"What is around me?"

Move into a folder

Use:

cd folder

cd means Change Directory.

For example, if you have:

projects/
    app.py
    python/

you can move into the python folder:

cd python

Your current location has now changed.

You can check it with:

pwd

And see what's inside with:

ls

Move back one folder

Use:

cd ..

The .. means:

"The folder above my current folder."

For example:

projects/
└── python/
    └── app.py

If you are inside python:

cd ..

you will move back to:

projects/

You can think of it like going up one level in the folder structure.

Move into a folder and back out

Let's practice.

Start by looking at where you are:

pwd

See what's there:

ls

Find a folder and move into it:

cd folder

Look around:

ls

Then go back:

cd ..

Check your location again:

pwd

You have now navigated through the filesystem using the terminal.

The four commands to remember

For now, these four commands are enough:

A useful mental model is:

pwd  → Where am I?
ls   → What's here?
cd   → Move somewhere
..   → Go up one level

Finding app.py

Let's connect this back to our Python program.

Suppose your project looks like this:

projects/
└── my-first-program/
    └── app.py

You can navigate to your project with:

cd projects

Then:

cd my-first-program

Check what's inside:

ls

You should see:

app.py

Now you can run your program:

python app.py

Notice the workflow:

Navigate to project
        ↓
Find app.py
        ↓
Run app.py
        ↓
See the output

This is why we're learning the terminal.

We're not memorizing random commands.

We're learning how developers move around their projects and run their code.

One More Useful Command

You can clear the terminal with:

clear

This doesn't delete anything.

It simply clears the text currently visible in your terminal.

Terminal Practice

Try completing this sequence:

pwd
ls

Find a folder you can enter, then:

cd folder
pwd
ls

Then go back:

cd ..
pwd

Finally, navigate back to your Python project and run:

python app.py

If you can do this without getting lost, you've learned enough terminal navigation for now.

We'll learn more commands when we actually need them.