Lab: Editing and Running Python Programs#

The goal of this lab is to get a working Python program running on your computer.

The Python Workflow#

Python does not require a separate compile step. The workflow is:

Write a .py file with a text editor.
Run it directly with python3.

There is no build or compile command.

Setting Up#

If Python 3 is not yet installed, download it from python.org. Open a terminal and verify:

$ python3 --version
Python 3.12.0

We recommend learning a terminal-based editor such as Vim or GNU Emacs. Visual Studio Code is acceptable, but it is most effective once you have mastered the basics of editing files and moving between the editor and the command-line shell.

The Interactive Shell#

Before writing a file, try the interactive shell. Type python3 at the terminal prompt:

$ python3
Python 3.12.0 (default, ...)
>>>

You are now at the Python REPL (Read-Evaluate-Print Loop). Type any expression and press Enter:

>>> 2 + 3
5
>>> "Hello!"
'Hello!'
>>> print("Hello, world!")
Hello, world!

Exit with quit() or Ctrl-D.

Your First Script#

Create a new file called hello.py with this content:
```
print("Hello, world!")
```
Run it from the terminal:
```
$ python3 hello.py
Hello, world!
```

The Painting Program#

Now run the painting program from A Sample Python Program.

Create a file called painting.py and type in the program.
Run it and verify you get the same output as shown in the sample run.
Run it a second time with different values (for example, length 15 and width 6.5) and check that the output is correct.

Calculation of Room Paint Requirements
Enter room length: 15
Enter room width: 6.5
The wall area is 344.0 square feet.
The ceiling area is 97.5 square feet.

Lab: Editing and Running Python Programs

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