query regarding OOP functionality in python

[Josiah Carlson]

> If you absolutely must have these features, stick to C++ or Java.

Or do something crazy like this...

Error = '''\
Received signature of: %s
Expected one of: %s'''

class polymorpher(object):
     def __init__(self):
         self._dict = {}
     def add_funct(self, funct, *argtypes):
         self._dict[argtypes] = funct
     def __call__(self, *args, **kwargs):
         t = tuple(map(type, args))
         try:
             f = self._dict[(t,)]
         except KeyError:
             raise TypeError(Error%(t, self._dict.keys()))
         return f(*args, **kwargs)


 >>> funct = polymorpher()
 >>> funct.add_funct(lambda *args:str(args), (int, int))
 >>> funct.add_funct(lambda *args:str(args), (float, int))
 >>> funct(1,2)
(<type 'int'>, <type 'int'>)
'(1, 2)'
 >>> funct(1.5, 6)
(<type 'float'>, <type 'int'>)
'(1.5, 6)'
 >>> funct(1, 1.5)
(<type 'int'>, <type 'float'>)
Traceback (most recent call last):
   File "<stdin>", line 1, in ?
   File "<stdin>", line 12, in __call__
TypeError: Received signature of: [<type 'int'>, <type 'float'>]
Expected one of: [((<type 'float'>, <type 'int'>),), ((<type 'int'>, 
<type 'int'>),)]
 >>>


Ahh, polymorphism.

  - Josiah