Why Does My Python Function Return `None`?

Function Returns None: Understanding Returned Values

In the Python programming language, every function inherently returns a value, even if the developer does not explicitly specify one. If no specific value is provided, Python assigns the default value of None to the function's return.

Consider the following code snippet:

def printmult(n):
    i = 1
    while i <= 10:
        print (n * i, end = ' ')
        i += 1
    
print(printmult(30))

This function, printmult(), takes an input value n and prints the result of multiplying n by integers from 1 to 10. The print statement within the function does not explicitly return a value. Therefore, when you call the function at the end of the script and assign its result to a variable (in this case, print(printmult(30))), the variable will contain None.

It is essential to understand the distinction between printing and returning. While printing displays the result on the output console, returning assigns a value to the function itself. To specify a specific return value, simply add a return statement with the desired value inside the function definition, as shown below:

def printmult(n):
    i = 1
    while i <= 10:
        print (n * i, end = ' ')
        i += 1
    return n * 10  # Example return value

By modifying the code in this way, you can now access the returned value when calling the printmult() function. Remember, it is always good practice to explicitly specify return values in your functions to avoid unexpected results and ensure that your code behaves as intended.

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