How to Solve the Issue of Functions Returning None in Python

Learn why your Python function may be returning `None` and how to fix it effectively with clear examples and simple language.
---

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Why is function within main function in python always returning "none" when it should return a float?

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Understanding the Issue: Functions in Python Returning None

As you embark on your journey to learn Python, you might encounter instances where your functions do not behave as expected. A common issue that beginners face is when a function within a main function returns None instead of the desired float value. This can be frustrating, especially when you're trying to implement a simple conversion, like turning time into a decimal format.

In this guide, we’ll dive into the reasons why this happens and how to fix it so you can successfully convert user input from a string to a float.

The Problem

You wrote a code snippet to convert time formatted as "HH:MM" into a decimal format, but you’re receiving None as the output. Let’s take a look at the problematic code:

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

The code intends to split the input string into hours and minutes, convert them into floats, and finally return the decimal representation of time. However, if the condition z > 0 holds true, your function will not reach the return statement, thus implicitly returning None.

Analyzing the Code

Return Issue

When you looked at the indentation and function definitions, you might have noticed that the error was not just in returning the result.

Missing Return: In the original code, there's a condition that does not lead to a return for the possible changes in z. If z is greater than zero, it calculates minutes but doesn't return a value subsequently.

Indentation Problems

Python relies heavily on indentation to define the scope of functions and loops. If your indentation is not correct, Python may fail to interpret your code as intended. For example, in the initial problematic version, the inner function convert(a) was not properly indented under main:

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

In Python, the code inside the function needs to be indented correctly; otherwise, it throws errors about expected indents.

The Solution

To fix these issues, you can simplify the code as follows and ensure proper indentation for the function and its logic:

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

Key Changes Made

Removed Unnecessary Conditions: The condition if z > 0 was removed because the math operation z / 60 handles all cases.

Proper Indentation: Each line inside the functions is correctly indented to avoid scope errors.

Direct Return Value: The function now directly returns the computed float value, making it cleaner and more efficient.

Conclusion

Functionality issues like returning None can often stem from logical missteps and indentation errors in Python. By understanding the flow of your function and ensuring that all code paths lead to a return statement, you can resolve this issue efficiently.

Keep practicing these concepts, and you will become proficient in Python.