how to code optional parameters python code example

Example 1: make parameter optional python

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

Example 2: optional arguments python

def some_function (self, a, b, c, d = None, e = None, f = None, g = None, h = None):
    #code