Python Arbitrary (Variable-Length) Arguments Explained with Examples

🔹 Arbitrary Arguments (*args)

Sometimes, we need a function that can accept **any number of arguments**. Python allows this by using the *args syntax. ➤ *args allows you to pass multiple **positional arguments** as a tuple. ➤ It helps when the number of arguments is **not fixed**.

Example:

# Function to sum numbers
def add(*args):
    s = 0
    for x in args:
        s += x
    return s

# Function calls
result1 = add(10, 20, 30, 40)
result2 = add(1, 2, 3)

print(result1)  # Output: 100
print(result2)  # Output: 6

🔹 Required Arguments with *args

You can also use **required arguments** along with *args. This means the first argument is **mandatory**, and the rest are optional.

Example:

# Function with a required argument
def avg(first, *rest):
    second = max(rest)
    return (first + second) / 2

# Function call
result = avg(40, 30, 50, 25)
print(result)  # Output: 45.0

🔹 Arbitrary Keyword Arguments (**kwargs)

Instead of positional arguments, you may need to pass **named arguments** (key-value pairs). ➤ **kwargs allows you to pass **any number of keyword arguments** as a dictionary. ➤ This is useful when you don’t know **how many named arguments** will be provided.

Example:

# Function with **kwargs
def addr(**kwargs):
    for k, v in kwargs.items():
        print(f"{k}: {v}")

# Function calls
addr(Name="John", City="Mumbai")
addr(Name="Raam", City="Mumbai", ph_no="9123134567", PIN="400001")

🔍 Key Takeaways:

• *args allows **multiple positional arguments**.
• **kwargs allows **multiple named arguments**.
• Use **required arguments** before *args/**kwargs.
• **args is a tuple, **kwargs is a dictionary.