Function Arguments

Python tutorial · PySpark.in

Function Arguments

Function arguments are the actual values supplied to a function at the time of its execution. They enable a function to operate on different data values without modifying the function definition. Arguments provide flexibility and reusability to function

Need for Function Arguments

To pass data into functions
To avoid writing multiple functions for similar tasks
To make functions dynamic and reusable

TYPES OF FUNCTION ARGUMENTS IN PYTHON

Python supports four main types of function arguments:

Positional Arguments
Keyword Arguments
Default Arguments
Variable-Length Arguments

POSITIONAL ARGUMENTS

Positional arguments are arguments that are passed to a function according to the position of parameters defined in the function. The order of arguments is significant in this type.

Characteristics

Order of arguments must match the order of parameters
Number of arguments must be equal to number of parameters
Most commonly used argument type

Example

```

def subtract(a, b):

return a - b

result = subtract(10, 5)

print(result)

```

Understanding the Example

10 is assigned to parameter a
5 is assigned to parameter b
Result depends on the order of values passed

Advantages

Simple and easy to use
Suitable for small functions

Limitations

Error-prone when many parameters are involved
Reduces code readabilityKeyword Arguments

Keyword arguments are arguments that are passed to a function using the parameter names, allowing values to be supplied in any order.

Characteristics

Order of arguments does not matter
Improves code readability
Reduces ambiguity

Example

```

def student(name, age):

print(name, age)

student(age=30, name="Rohan")

```

Understanding the Example

Python matches arguments directly with parameter names
Order of arguments is ignored

Advantages

Clear and self-documenting
Ideal for functions with many parameters

Limitations

Slightly longer syntax
Parameter names must be remembered

DEFAULT ARGUMENTS

A default argument is a parameter that assumes a predefined value if no corresponding argument is provided during function call. Default values are assigned at the time of function definition.

Characteristics

Makes arguments optional
Default value is used only when argument is not passed

Example

```

def greet(name="Student"):

print("Hello", name)

greet()

greet("Megha")

```

Understanding the Example

If no argument is passed, default value is used
If argument is provided, default value is overridden

Advantages

Simplifies function calls
Reduces number of arguments

Limitations

Care required while using mutable default values

VARIABLE-LENGTH ARGUMENTS

Variable-length arguments allow a function to accept any number of arguments, making the function more flexible.

Types of Variable-Length Arguments

Non-keyword variable-length arguments (*args)
Keyword variable-length arguments (**kwargs)

1. *args (Non-keyword Variable-Length Arguments)

*args allows multiple arguments to be passed to a function, which are internally stored as a tuple.

Example

```

def total(*numbers):

sum = 0

for i in numbers:

sum += i

return sum

print(total(1, 2, 3, 4))

```

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

**kwargs allows a function to accept any number of keyword arguments, which are stored as a dictionary.

Example

```

def details(**data):

for key, value in data.items():

print(key, value)

details(name="Rohan", age=20, course="Msc")

```

Advantages

Highly flexible
Useful for library and API development

Limitations

Can reduce code clarity if overused

Function Arguments