troubleshooting.md

layout	default
title	Troubleshooting
parent	Setup
nav_order	3
permalink	/setup/troubleshooting/

Setup Troubleshooting

python is not recognized

Use the platform-specific command from the setup guide: python3 on many macOS/Linux systems or py on Windows. Restart the terminal after installation.

The wrong Python version runs

Check all available commands and use the one that points to the intended Python 3 installation. Do not remove system Python files.

The virtual environment will not activate

Confirm that you are in the project folder and that .venv exists. You can still run the environment directly:

.venv/bin/python hello.py

On Windows:

.venv\Scripts\python.exe hello.py

A program does not run

Read the complete error message. Note the file name and line number, check indentation, and reproduce the error with the smallest possible program.

Python says it cannot open the file

The terminal is probably in a different folder. Use pwd on macOS/Linux or Get-Location on PowerShell. Then list files with ls or Get-ChildItem. Use cd to enter the folder containing your .py file.

The file is really named hello.py.txt

Some editors hide filename endings. Ask the editor or file manager to show extensions and save the file exactly as hello.py.

I see >>>

You are inside Python's interactive prompt, not the normal terminal. Type exit() and press Enter. Then run the saved file with python hello.py, py hello.py, or python3 hello.py.

PowerShell blocks .venv activation

Activation is convenient but not required. Run the environment's interpreter directly:

.venv\Scripts\python.exe hello.py

Do not copy random security-setting commands from the internet. Ask a parent, teacher, or administrator when using a managed computer.

---

Back to Setup · Terminal Basics