Python Functions with Special Parameters

Python have the special forms of parameters in functions. These special forms of parameters are Args and Kwargs. Args is a special parameter through which any number of positive arguments packed into a tuple. Through Kwargs any number of Keyword Arguments packed into a dictionary.

Args is represented by *args

Kwargs is represented by **Kwargs

Args

*args is a special syntax in function definitions which is used to pass a non-keyworded variable number of arguments to a function. To take variable number of arguments, * is used in the syntax. With *args, any number of arguments can be appended on to the current parameters.

Python Code:

def fruits(*args):  
    for arg in args:  
        print (arg) 
    
fruits(‘Mango’, ‘Apple’, ‘Guava’, ‘Banana’)

Output:

Mango

Apple

Guava

Banana

We can also make iterative statements by using *args. In the given example, we are defining two statements. In which first is non iterative and second is iterative statements. The values are assigned by calling the function.

Python Code:

def numbers(arg1, *args): 
    print (“First number: “, arg1) 
    for arg in args: 
        print(“Next number: “, arg) 
  
numbers(‘one’, ‘two’, ‘three’, ‘four’, ‘five’)

Output:

First number:  one

Next number:  two

Next number:  three

Next number:  four

Next number:  five

Kwargs

Kwargs is a special syntax in function definitions which is used to pass keyworded, variable-length argument list. In syntax we use double star before Kwargs. It is represented as **Kwargs.

Double star allows us to pass values through keyword arguments. Kwargs is a dictionary which maps each keyword to the value which we pass alongside it. When we call the iterative function, there will not be any order.

Python Code:

def winner(**kwargs):  
    for key, value in kwargs.items(): 
        print ("%s : %s " %(key, value)) 
  
winner(first ='ross', second ='john', third='mike')

Output:

first : ross

second : john

third : mike