Why Do Python Functions Sometimes Return `None`?

Why Functions May Return None

In Python, functions are expected to return a value. If no explicit return statement is provided, the default return value is None. However, this can lead to confusion, especially when the function is expected to perform certain actions without explicitly returning anything.

Consider the following code:

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

print(print_multiplication(30))

This function prints the multiplication table for the number 30. The print statement within the function prints each product without using a return statement. Consequently, the function returns None by default.

Understanding the Return Value

The print statement is intended to display the multiplication table, but it does not return anything. As a result, print_multiplication(30) also returns None. When we attempt to print the return value, None is printed instead of the expected output.

Correcting the Function

To fix this issue, we need to specify the desired return value. Since the function is intended to perform a task without returning specific data, we can use the None keyword explicitly:

def print_multiplication(n):
    i = 1
    while i <= 10:
        print(n * i, end=' ')
        i += 1
    return None

print(print_multiplication(30))

By explicitly returning None, we ensure that the function follows the Python convention of returning a value without providing any specific data. Now, when we print the return value, it will correctly output None.

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