Extended function argument syntax

• Extended function argument syntax in Python allows for more flexible and readable function definitions and calls.
• It includes several features such as positional arguments, keyword arguments, default values, *args, **kwargs, and keyword-only arguments.
• These two special identifiers (named *args and **kwargs) should be put as the last two parameters in a function definition. Those two special parameters are responsible for handling any number of additional arguments (placed next after the expected arguments) passed to a called function.

Types of Arguments:

1. Positional arguments

• These are the most straightforward and are matched in order.

def func(a, b, c):
    print(a, b, c)

func(1, 2, 3)  # Outputs: 1 2 3

2. Default Arguments

• You can provide default values for arguments, which makes them optional when calling the function.

def func(a, b=2, c=3):
    print(a, b, c)

func(1)      # Outputs: 1 2 3
func(1, 4)   # Outputs: 1 4 3

*args

• if refers to a tuple of all additional, not explicitly expected positional arguments, so arguments passed without keywords and passed next after the expected arguments.
• In other words, *args collects all unmatched positional arguments.
• The single asterisk is used to denote variable-length positional arguments.
• When a function uses *args, it can accept any number of positional arguments, which are then passed to the function as a tuple.

**kwargs

• It refers to a dictionary of all unexpected arguments that were passed in the form of keyword=value pairs. Likewise, **kwargs collects all unmatched keyword arguments.
• The double asterisk is used to denote variable-length keyword arguments.
• When a function uses **kwargs, it can accept any number of keyword arguments, which are then passed to the function as a dictionary.

In Python, asterisks are used to denote that args and kwargs parameters are not ordinary parameters and should be unpacked, as they carry multiple items.

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*args refers to a tuple of all not explicitly expected arguments; **kwargs refers to a dictionary of all not explicitly expected keyword arguments

def combiner(a, b, *args, **kwargs):
    print(a, type(a))
    print(b, type(b))
    print(args, type(args))
    print(kwargs, type(kwargs))


combiner(10, '20', 40, 60, 30, 445, argument1=50, argument2='66')

Refer q1.py

Forwarding arguments to other functions

• Refer q2.py
• Refer q3.py