how to indicate optional parameter in python3 function code example

Example 1: python optional parameters

def my_func(a = 1, b = 2, c = 3):
	print(a + b + c)
    
my_func()
#OUTPUT = 6

my_func(2)
#This changes the value of a to 2
#OUTPUT = 7

my_func(c = 2)
#This changes the value of c to 2
#OUTPUT = 5

Example 2: make parameter optional python

def myfunc(a,b, *args, **kwargs):
   for ar in args:
      print ar
myfunc(a,b,c,d,e,f)