Variable Number of Arguments

Sometimes we don’t know how many Arguments we will need to pass to a function. In this case we can use *args and **kwargs to accept any number of positional and keyword Arguments.

*args is used to accept any number of positional Arguments. For example:

def func(*args):
    pass
 
func(1, 2, 3) # args will be (1, 2, 3)

**kwargs is used to accept any number of keyword Arguments. For example:

def func(**kwargs):
    pass
 
func(x=1, y=2, z=3) # kwargs will be {'x': 1, 'y': 2, 'z': 3}

NOTE 1: *args and **kwargs can be used together. For example:

 def func(*args, **kwargs):
     pass
 
 func(1, 2, 3, x=1, y=2, z=3) # args will be (1, 2, 3) and kwargs will be {'x': 1, 'y': 2, 'z': 3}

NOTE 2: *args and **kwargs can be used when calling a function to unpack a list or a dictionary and pass its elements as positional or keyword Arguments to the function. For example:

 def func(x, y, z):
     pass
 
 l = [1, 2, 3]
 d = {'x': 1, 'y': 2, 'z': 3}
 
 func(*l) # This is equivalent to func(1, 2, 3)
 func(**d) # This is equivalent to func(x=1, y=2, z=3)

Please also note that the keywords args and kwargs are just a convention. You can use any other name you want.

You can also declare a function that accepts a fixed number of positional Arguments and any number of keyword Arguments. For example:

def func(x, y, **kwargs):
    pass
 
func(1, 2, z=3) # kwargs will be {'z': 3}