What is Python return statement

The return statement in Python is used to exit a function and send a value or object back to the caller. It marks the end of the function’s execution and specifies what the function will output.

Syntax

def function_name(parameters):
    # code
    return value

• return value: Specifies the value or object to return to the caller.
• If no return statement is used, the function returns None by default.

Key Points

1. Returning a Value: A function can return a single value, a list, a tuple, or any other data structure.

   def add(a, b):
       return a + b
   
   result = add(3, 4)
   print(result)  # Output: 7
   

2. Multiple Return Values: Python allows returning multiple values by separating them with commas. These are returned as a tuple.

   def calculate(a, b):
       return a + b, a - b, a * b
   
   result = calculate(5, 3)
   print(result)  # Output: (8, 2, 15)
   

3. Returning Nothing: If no return is used or return is called without a value, the function returns None.

   def greet():
       print("Hello")
   
   result = greet()
   print(result)  # Output: None
   

4. Using return to Exit a Function Early: A return statement can be used to terminate a function before it reaches the end.

   def check_positive(num):
       if num > 0:
           return "Positive"
       return "Not Positive"
   
   print(check_positive(5))  # Output: Positive
   print(check_positive(-3))  # Output: Not Positive
   

Example Use Cases

1. Return a Calculated Result:

   def square(num):
       return num ** 2
   
   print(square(4))  # Output: 16
   

2. Return Conditional Values:

   def check_even(num):
       return "Even" if num % 2 == 0 else "Odd"
   
   print(check_even(7))  # Output: Odd
   

3. Return a Complex Data Structure:

   def get_user_data():
       return {"name": "Alice", "age": 30}
   
   user = get_user_data()
   print(user["name"])  # Output: Alice
   

Best Practices

• Always use return to explicitly indicate what a function should output.
• Avoid unnecessary return statements unless they add clarity or functionality.
• Use meaningful return values that make the function’s purpose clear.

The return statement is a fundamental tool in Python for building reusable and modular code.