Function with Return Value in Python

In Python, a function with a return value is a function that sends back a value to the caller using the return statement. This allows the function to produce a result that can be used later in the program. Functions that return values are useful for encapsulating calculations or operations that need to be used repeatedly.

Defining a Function with Return Value

You can define a function that returns a value by including the return statement in its body. The value specified in the return statement is sent back to the point where the function was called.

Syntax

def function_name(parameters):
    # Code block (function body)
    return value  # The value to be returned

Example of a Function with Return Value

Here’s a simple example of a function that calculates the square of a number and returns the result:

def square(number):
    """This function returns the square of the given number."""
    return number ** 2  # Return the square of the number

# Calling the function and storing the result
result = square(5)
print(result)

Output:

25

Breakdown of the Example

1. Function Definition:

   • The function square takes one parameter, number.
   • The body of the function calculates the square of number using number ** 2 and returns the result.

2. Function Call:

   • The function is called with the argument 5, and the result is stored in the variable result.
   • When square(5) is executed, it returns 25, which is printed to the console.

Using Return Values

The return value of a function can be used in various ways, such as:

• Storing it in a variable.
• Using it in expressions.
• Returning it as an argument to another function.

Example of Using Return Values

def multiply(a, b):
    """This function returns the product of two numbers."""
    return a * b

# Using the return value in an expression
result = multiply(3, 4) + 2
print(result)  # Output: 14

In this example, the multiply function returns the product of 3 and 4. The returned value is then added to 2, resulting in 14.

Returning Multiple Values

Python allows you to return multiple values from a function as a tuple. This can be useful when you want to return several related results.

def calculate_stats(numbers):
    """This function returns the sum and average of a list of numbers."""
    total = sum(numbers)
    average = total / len(numbers)
    return total, average  # Returning multiple values

# Calling the function
stats = calculate_stats([10, 20, 30])
print(f"Total: {stats[0]}, Average: {stats[1]}")

Output:

Total: 60, Average: 20.0

In this example, the calculate_stats function returns both the total and average of the list of numbers. The returned values are captured as a tuple, which can be accessed by indexing.

Summary

• A function with a return value uses the return statement to send a value back to the caller.
• The returned value can be used in expressions, assigned to variables, or passed to other functions.
• You can return multiple values from a function, which are returned as a tuple and can be accessed using indexing.

Functions with return values are fundamental in Python programming, enabling you to create modular code that can perform computations and return results for further use.