Function Overloading

Default Arguments

Default arguments allow you to specify a default value for a function parameter. If the caller doesn’t provide a value for that parameter, the default value is used.

def greet(name, greeting="Hello"):
  print(f"{greeting}, {name}!")

greet("Alice")  # Output: Hello, Alice!
greet("Bob", "Good morning")  # Output: Good morning, Bob!

Important Considerations:

• Order Matters: Default arguments must come after non-default arguments in the function definition. This is because Python matches arguments based on their position.

# Correct
def func(a, b=2):
    pass

# Incorrect - will raise a SyntaxError
def func(a=1, b):
    pass

• Mutability: Be cautious when using mutable objects (like lists or dictionaries) as default arguments. The default value is created only once when the function is defined. Subsequent calls will modify the same object. Mutable Default Arguments

• None as a Default: None is a good choice as a default for parameters that might not always be needed, avoiding the mutability issues mentioned above.

def process_data(data=None):
  if data is None:
      data = 1 #Create a new list if none is provided
  # ... process data ...

Related Notes:

• Function Definitions
• Function Calls