Adding a method to an instance

[Rainer Deyke]

"Bryan Mongeau" <bryan at eevolved.com> wrote in message
news:G2%n6.360714$JT5.11606234 at news20.bellglobal.com...
> Quick one for you guys:
>
> I would like to add a method to an instantiated class.
>
> class foo:
>   def __init__(self):
>     self.bar = 123
>
> f = foo()
>
> Now to add a method to the instance f of class foo:
>
> def newMethod(self):
>   print self.bar

In this particular case:

f = foo()

def newMethod(self=f):
  print self.bar

f.newMethod = newMethod


In general:

def add_method(instance, method, name):
  # We want nested scopes!  We want nested scopes!  We want nested scopes
  # In the absence of nested scopes, there is no easy way to pass on
  # non-keyword args to 'method'.
  def call_method(instance=instance, method=method, **kwargs):
    method(instance, **kwargs)
  setattr(instance, name, call_method)

add_method(f, newMethod, 'newMethod')


--
Rainer Deyke (root at rainerdeyke.com)
Shareware computer games           -           http://rainerdeyke.com
"In ihren Reihen zu stehen heisst unter Feinden zu kaempfen" - Abigor