1. Keywords:

  • Keywords are reserved words in Python that have special meanings and cannot be used as variable names or function names.

  • They define the syntax and structure of the language. Here are some common examples:

    • def: Used to define functions.
    • if: Used for conditional statements.
    • for: Used for loop iterations.
    • else: Used for alternative execution blocks.
    • return: Used to return values from functions.
    • and, or, not: Used for logical operations.

  • A complete list of keywords can be found in the official Python documentation https://docs.python.org/3/library/keyword.html.

2. Multiple Output:

  • While Python functions typically return a single value using the return statement, there are a few ways to achieve multiple outputs:

    • Returning a Tuple: You can pack multiple values into a tuple and return the tuple itself.

      Python
      def calculate_area_and_perimeter(length, width):
    area = length * width
    perimeter = 2 * (length + width)
    return area, perimeter  # Returning a tuple

result = calculate_area_and_perimeter(5, 3)
area, perimeter = result  # Unpacking the tuple

print(f"Area: {area}, Perimeter: {perimeter}")

    • Modifying Global Variables (Not Recommended): You can modify global variables within the function, but this can lead to unintended side effects and is generally not recommended for good programming practices.

    • Using Multiple Return Statements (Limited Use): In some specific cases, you can use multiple return statements within a function, but this can make the code harder to read and reason about.

3. Documentation:

  • Writing good documentation is essential for maintaining clean and understandable code. Here are some common documentation practices in Python:

    • Docstrings: Docstrings are multi-line strings placed at the beginning of functions, modules, or classes. They explain the purpose, usage, and parameters of the code element. Docstrings can be accessed using the __doc__ attribute.

      Python
      def greet(name):
    """Greets the user by name.

    Args:
        name: The name of the person to greet (str).

    Returns:
        A string containing the greeting message.
    """
    message = f"Hello, {name}!"
    return message

    • Comments: Inline comments using # can be used to explain specific code sections within the program.

  • Good documentation improves code readability, maintainability, and collaboration by making it easier for others (and yourself in the future) to understand what the code does and how to use it.

Key Points:

  • Keywords are essential building blocks of Python syntax.
  • There are several approaches to achieving multiple outputs from functions, with returning tuples being the most common and recommended approach.
  • Writing good documentation (docstrings and comments) is crucial for clear and maintainable code.