Converting Dijkstra's Algorithm from Python3 to CircuitPython

Discover how to adapt Dijkstra's Algorithm for CircuitPython using TI-84 calculators, avoiding unsupported methods. Learn practical coding techniques and alternatives to dictionary methods!
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Converting Dijkstra's Algorithm from Python3 to CircuitPython

Programming on devices like the TI-84 Python edition calculators can be a bit tricky, especially when certain basic features of Python are not available. One common challenge developers face is adapting code to work within the constraints of CircuitPython, a simplified version of Python designed for microcontrollers.

In this article, we will explore how to refactor Dijkstra's Algorithm, a popular algorithm used to find the shortest paths between nodes in a graph, specifically for use in CircuitPython. We'll address some of the limitations you'll encounter, such as the lack of support for methods like items() and values() commonly used with dictionaries in Python.

Understanding Dijkstra's Algorithm

Before we dive into the code, let’s briefly understand what Dijkstra's Algorithm does. The algorithm's primary goal is to determine the shortest path from a starting node to all other nodes in a weighted graph. Here’s a quick breakdown:

Nodes represent points in the graph.

Edges connecting the nodes have associated weights (distances).

The algorithm keeps track of unvisited nodes and calculates the shortest distance incrementally.

Now that we know the foundational concepts of the algorithm, let’s examine the original Python implementation.

Original Python Implementation

Here's the standard version of Dijkstra's Algorithm using Python3 with dictionary methods:

[[See Video to Reveal this Text or Code Snippet]]

Converting to CircuitPython

Now, let's adapt this code for CircuitPython, where some dictionary methods like items() and values() are not supported.

Here’s the modified version for TI-Python:

[[See Video to Reveal this Text or Code Snippet]]

Key Refactor Points

Iterating Over Dictionaries

In the original Python implementation, the line:

[[See Video to Reveal this Text or Code Snippet]]

Can be refactored in CircuitPython simply to check each key directly:

[[See Video to Reveal this Text or Code Snippet]]

This way, you avoid using the unsupported items() method while keeping your list comprehensions simple and clear.

Printing Sorted Items

The line:

[[See Video to Reveal this Text or Code Snippet]]

Can be transformed into a more CircuitPython-friendly version as follows:

[[See Video to Reveal this Text or Code Snippet]]

This uses dictionary comprehension, which is both efficient and readable, providing a clear view of the visited nodes in sorted order.

Conclusion

Adapting your code to different environments or languages can seem daunting, but with a structured approach, it can be straightforward. By understanding the limitations of the tools at hand, like the absence of certain dictionary methods in CircuitPython, you can find effective solutions to achieve the same functionality.

Dijkstra's Algorithm is a powerful tool for network analysis, and by refactoring it for CircuitPython, you can utilize your programming skills even on a TI-84 calculator. Happy coding!