how to make one parameter optional in afunction in python code example

Example 1: python optional arguments

def myfunc(a,b, *args, **kwargs):
      c = kwargs.get('c', None)
      d = kwargs.get('d', None)
      #etc
myfunc(a,b, c='nick', d='dog', ...)

Example 2: optional arguments python

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