Python_G-008. Function

Definition	A block of reusable code that performs a specific task.	def function_name(parameters):
Syntax	def function_name():	def greet(name):
Calling a Function	Executing a function by using its name followed (by parentheses and arguments if needed)	greet("Alice")
Parameters	Variables listed inside the parentheses in the function definition.	def add(a, b):
Arguments	Values passed to the function when calling it.	add(3, 5)
Return Statement	Used to return a value from a function.	return a + b
Default Parameters	Parameters with default values that are used if no argument is provided.	def greet(name="Guest"):
Keyword Arguments	Arguments passed by specifying the parameter name.	describe_pet(pet_name="Whiskers", animal_type="cat")
Lambda Functions	Small anonymous functions defined using the lambda keyword.	square = lambda x: x * x
Docstrings	A special string that describes the function's purpose and behavior, placed at the beginning of the function body.	"""This function greets the person with the given name."""

Example Code:

# Defining a function
def greet(name="Guest"):
    """This function greets the person with the given name."""
    print(f"Hello, {name}!")

# Calling the function
greet()  # Output: Hello, Guest!
greet("Alice")  # Output: Hello, Alice!

# Function with parameters and return value
def add(a, b):
    """This function returns the sum of two numbers."""
    return a + b

# Calling the function
result = add(3, 5)  # Output: 8
print(result)

# Lambda function
square = lambda x: x * x
print(square(5))  # Output: 25