The *args and **kwargs allow you to pass multiple arguments or keyword arguments to a function. We can pass a varying number of arguments to a function. We can simply pass a list or a set of all the arguments to your function. But whenever we call the function we’ll also need to create a list of arguments to pass to it. This can be inconvenient, especially if we don’t know up front all the values that should go into the list. The *args can be really useful, because it allows you to pass a varying number of positional arguments to your script. The * is called unpacking operator .The iterable object we’ll get used the unpacking operator * is not a list but is a tuple. Both the tuple and list support slicing and iteration. In fact, tuples are very different in at least one aspect, i.e., lists are mutable while tuples are not.

Example for *args :

def myfun(*argv):  
	for arg in argv:  
		 print (arg) 
myfun('Hello', 'Welcome', 'to', 'python')  

Output :  Hello Welcome to python

The **kwargs works just like args, however, instead of accepting positional arguments it accepts keyword (or named) arguments. Similar to args, kwargs is just a name that can be changed to whatever you want. What is important here is the use of the unpacking operator(**).

Example for *kwargs :

def myfun(**kwargs):  
d={}
for key,value in kwargs.items(): 
d[key]=value
print(d) 
myfun(first ='welcome', mid ='to’, last='python')   

output:

{'mid': 'to', 'last': 'python', 'first': 'welcome'}

The double asterisk form of **kwargs is used to pass a key worded, variable-length argument dictionary to a function.

Like non-default arguments have to precede default arguments, so *args must come before **kwargs.

The correct order for your parameters is:

1. Standard arguments.
2. *args arguments.
3. **kwargs arguments.

Author: STEPS