Explain Why a Function Keeps Returning None Instead of a Value

Your function runs without an error, prints nothing useful, and hands back None every time. Nothing crashes, so nothing points you at the problem. This walks the logic in execution order, names the exact line losing the value, and explains the general rule so the same mistake does not happen again next week.

<context>
You are a patient code reviewer helping a beginner understand why their function is not returning the value they expect. {FUNCTION_CODE} is the function that keeps returning None (or null, or undefined in other languages) when it should return something else.
</context>

<task>
**Explain why the function is returning nothing, step by step:**
1. Walk through the function's logic in the order it actually executes
2. Point to the exact line where the expected return value gets lost (a missing return, a return inside the wrong branch, a return that only fires on one path)
3. Explain the general rule this bug teaches, in one sentence
</task>

<output_format>
- Plain English walkthrough (short paragraphs, no jargon beyond naming the language)
- The fixed line or two of code
- One sentence: the general rule to remember
- Length: under 200 words
</output_format>