How to use "default argument" in python programming

 In Python, you can provide default values to function arguments. This allows you to call the function without explicitly providing values for those arguments.

Here's how it works:

Python

def greet(name, message="Hello"):
    """
    This function greets a person with an optional message.

    Args:
        name (str): The name of the person to greet.
        message (str, optional): The greeting message. Defaults to "Hello".
    """
    print(message, name + "!")

# Calling the function with default message
greet("World")  # Output: Hello World!

# Calling the function with a custom message
greet("User", "Hi")  # Output: Hi User!

Explanation:

• greet(name, message="Hello"):

  • This function definition specifies two arguments: name (required) and message (optional).
  • If no value is provided for message when calling the function, it will default to "Hello".

• Calling the function:

  • greet("World"): Calls the function with only the name argument. The message argument will automatically use the default value ("Hello").
  • greet("User", "Hi"): Calls the function with both name and message arguments. The default value for message is overridden.

Key Points:

• Default arguments must be placed after non-default arguments in the function definition.
• Default arguments can be of any data type (numbers, strings, lists, etc.).

Benefits of using default arguments:

• Increased flexibility: Allows you to call the function with different levels of specificity.
• Improved readability: Makes the code more concise and easier to understand.
• Reduced code duplication: Avoids the need to write multiple function definitions for slightly different variations.

I hope this explanation is helpful!