The best tool for Dorothea to learn test-based Python coding, alongside being able to write and run her code in a browser, would be Trinket.
Trinket is designed specifically for educational purposes and allows users to write, run, and share Python code directly in their browser. It provides a user-friendly interface and has various tutorials that can help beginners learn coding concepts effectively.
While Python Tutor is great for visualizing code execution and debugging, it doesn’t provide a complete coding environment for writing and running scripts. Google Play Store is not a coding tool, and CodeSkulptor3 is primarily focused on running Python code but may not have the same level of tutorials and educational resources built-in as Trinket.
Thus, Trinket is the most suitable option for her needs.