A little present.

[Neel Krishnaswami]

Michael Hudson <mwh21 at cam.ac.uk> wrote:
> 
> The idea is that after a call to X(func,...) there are a number of
> `holes' (notated by an empty tuple) in the arglist that can be `filled
> in' by subsequent calls (to what X returns). This means you can't
> presupply the empty tuple to func, but I couldn't think of a better
> way.

Here's one:

class Hole:
    pass

Then change the test

  def __init__(self, func, *args):
    [...]
    if args[i] == ():

to 

  def __init__(self, func, *args):
    [...]
    if args[i] is Hole:

Since Hole is a unique object, there isn't anything else that 'is'
Hole. If you ever find yourself needing to pass Hole as an argument,
then add "hole=Hole" to the __init__ arglist and let people change
what the hole object by overriding the default argument.
 

Neel