Python Function Arguments

1. Positional Arguments

def display_info(name, age):
    print(f"Name: {name}, Age: {age}")

display_info("Alice", 25)

Arguments are passed in the order defined by the function.

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2. Keyword Arguments

def display_info(name, age):
    print(f"Name: {name}, Age: {age}")

display_info(age=25, name="Alice")

Arguments are passed using parameter names, improving readability and flexibility.

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3. Default Arguments

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

greet()
greet("Bob")

Default values are used when arguments are not supplied.

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4. Required Arguments

def login(username, password):
    print(f"User: {username}")

login("admin", "1234")
# login("admin")  # Raises TypeError

Arguments without defaults must be provided.

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5. *Variable-Length Positional Arguments (args)

def calculate_sum(*numbers):
    return sum(numbers)

print(calculate_sum(1, 2, 3))      # 6
print(calculate_sum(5, 10, 15, 5)) # 35

*args collects extra positional arguments into a tuple.

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6. **Variable-Length Keyword Arguments (kwargs)

def user_profile(**details):
    for key, value in details.items():
        print(f"{key}: {value}")

user_profile(name="Alice", role="Developer", level="Senior")

**kwargs collects extra keyword arguments into a dictionary.

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7. **Combining Normal, *args, and kwargs

def full_profile(name, *skills, **info):
    print("Name:", name)
    print("Skills:", skills)
    print("Details:", info)

full_profile("Alice", "Python", "ML", age=30, city="Toronto")

Order of parameters must follow: **normal → *args → kwargs

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8. Positional-Only Arguments (Python 3.8+)

def divide(a, b, /):
    return a / b

print(divide(10, 2))
# divide(a=10, b=2)  # Raises TypeError

Parameters before / must be positional-only.

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9. Keyword-Only Arguments

def configure(*, mode="light"):
    print(f"Mode: {mode}")

configure(mode="dark")

Parameters after * must be specified as keyword arguments.

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10. Argument Unpacking

def multiply(a, b, c):
    return a * b * c

values = (2, 3, 4)
print(multiply(*values))  # Output: 24

data = {"a": 1, "b": 2, "c": 3}
print(multiply(**data))   # Output: 6

* and ** can unpack tuples/lists and dictionaries directly into function arguments.

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