functions

• In Python, functions are reusable blocks of code that perform a specific task.
• They promote code modularity, readability, and maintainability by encapsulating logic into well-defined units.
• The def keyword is used to define a function.
• Function Arguments
  • Functions can accept zero or more arguments (inputs) that provide data to the function.
  • Arguments are defined within the parentheses after the function name in the definition.
  • When calling the function, you pass the actual values (arguments) you want to use within parentheses.
• Return Values
  • Functions can optionally return a value using the return statement. The returned value becomes the output of the function call.
  • If no return statement is present, the function implicitly returns None.
• Using Functions Effectively
  • Break down complex problems into smaller, well-defined functions.
  • Give functions descriptive names that reflect their purpose.
  • Use docstrings to explain what the function does and how to use it.
  • Consider using default arguments to provide optional parameter values.
• Key Points
  • Functions improve code reusability by allowing you to write a block of code once and call it multiple times with different inputs.
  • Arguments provide flexibility in how you use a function.
  • Return values enable functions to provide data back to the calling code.
  • Docstrings enhance code readability and understanding.

def greet(name):
    """This function greets a person by name."""
    print(f"Hello, {name}!")

# Call the function with different names
greet("chaitu-ycr")
greet("Bob")
greet("Charlie")

def greet(name): """This function greets a person by name.""" print(f"Hello, {name}!") # Call the function with different names greet("chaitu-ycr") greet("Bob") greet("Charlie")

• def greet(name):: This line defines the function named greet. The parameter name specifies that the function expects a value to be passed when it's called.
• """This function greets a person by name.""": This is a docstring, an optional line that provides a brief description of the function's purpose. It improves code readability and understanding.
• print(f"Hello, {name}!"): This indented code block defines the function's body. The code within this block executes when the function is called.
• greet("chaitu-ycr"), greet("Bob"), etc.: These lines call the greet function with different arguments ("chaitu-ycr", "Bob", etc.) for the name parameter.

def add(x, y):
    """This function adds two numbers."""
    return x + y

result = add(5, 3)  # result will be 8
print(result)

def add(x, y): """This function adds two numbers.""" return x + y result = add(5, 3) # result will be 8 print(result)