The difference between “ *args and **kwargs “ in our Python functions

Mohammed Mokhtar — Wed, 25 Sep 2024 20:46:09 +0000

Let's start with the normal functions, for which we know what we are sending in our main body to the integrated function. For example, we are going to send 3 variables and print them in our function:

def func_print( x , y , z ): #we have created a function which receives 3 variables 
   print( x )
   print( y )
   print( z )

func_print("mohammed" , 39 , ['id ', 10235 , "name"]) # we sent string , integer, and list 

"""
output will be mohammed
               39
               ['id ', 10235 , "name"]
"""

**Now what will happen if we send another variable to our function?

So to fix that, we will use “*args“ instead of multiple variables:

def func_print( *args ): #we have created a function which receives 3 variables 
   for y in args :
    print(y)

func_print("mohammed" , 39 , ['id ', 10235 , "name"] , 90 ) # we sent string , integer, and list 

"""
output will be mohammed
               39
               ['id ', 10235 , "name"]
               90
"""

But what does “*args“ actually make?!
*args allows you to pass a variable number of positional arguments to a function.

These arguments can be integers, strings, lists, dictionaries, or any other data type.

Internally, it collects the arguments passed into a tuple, regardless of the type of the arguments. That is why we have used a for loop to print our data.

But hold on, what should we do if we want to send keyword arguments?!🤔
“**kwargs” will be the solution

“**kwargs” captures keyword arguments as a dictionary, where the keys are the argument names and the values are the corresponding argument values.

This is useful when you want to handle a varying number of named arguments.

let’s say we want to send key-value variables just like dictionary

def func_print( **kwargs ): 
   for x , y in kwargs.items() :
    print(f"The key is {x} while the value is {y}")


func_print(location="Borneo", cause="Illegal logging", area="National Park" )

As you see, they save those values in a dictionary.

We have a problem; we can’t send number of dictionaries to function as it will raise an error. So what is the solution?!
It’s simple; we have to place ** before the dictionary name.

Let’s say we want to use Positional arguments & Keyword arguments together

def func_print(*args , **kwargs ): 
   ## args part
    print("__________________Args Shape________________________")
    print(args)                                                     # Tuple
    print("__________________Args Values________________________")
    for x in arguments:
      print(x)
  ## kwards part
    print("__________________Kwargs Shape________________________")
    print(kwargs)                                                   # Dictionary
    print("__________________Kwargs Values _____________________")
    for x , y in kwargs.items() :
       print(f"The key is {x} while the value is {y}")

dict_new = dict(location="Borneo", cause="Illegal logging", area="National Park" )
func_print(  "Loss of biodiversity", "Climate change" , "Disruption of ecosystems" , name = "Ahmed," , **dict_new  )

Finally, in that piece:
The difference between *args & **kwargs is:
args: Collects positional arguments into a tuple.
**kwargs: Collects keyword arguments into a dictionary.
**kwargs: is designed for keyword arguments (key-value pairs), not for a single positional argument like a dictionary.
You need to use the * operator to unpack the dictionary into keyword arguments, which **kwargs can accept.
You can use both together in a function to handle a flexible number of both positional and keyword arguments.
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The difference between “ *args and **kwargs “ in our Python functions