title: Python decorator with arbitrary positioned parameter of decorated function
body: <p>What would be the way for python decorator to become "polymorphic"? What I mean is it seeks for one exact parameter of decorated function, does something to/with it, then passes the modified parameter to the function. However, this parameter with common name has arbitrary position in any decorated function.</p>
  
  <pre><code>def decorator(func):
      def wrapper(exactly_this_param, *args):
          new = do_smth(exactly_this_param)
          return func(exactly_this_param=new, *args)
      return wrapper
  
  @decorator
  def func1(a, b, exactly_this_param, c):
      # does something
  
  @decorator
  def func2(exactly_this_param):
      # does something
  
  @decorator
  def func3(a, b, c, d, e, exactly_this_param, *args, **kwargs):
      # does something
  </code></pre>