Linking Dictionary Values

[Jesse F. W]

Greetings to all you large snake fanciers,
Maan M. Hamze wrote:
> Is it possible to link Dictionary values of each key into a text file?
This is probably more tricky and cute than you really need, but it is 
so tricky and cute I could not resist posting it on the list.

In Python 2.2 and later...

import types, os

class FileDict(dictionary):
	def __getitem__(self, key):
		value=dictionary.__getitem__(self, key)
		if os.access(value, os.R_OK):
			return open(value).read()
		raise ValueError, 'Value is not a readable file!'

class FunctionDict(dictionary):
	def __getitem__(self, key):
		return dictionary.__getitem__(self, key)()

class FileAndFunctionDict(dictionary):
	def __getitem__(self, key):
		value=dictionary.__getitem__(self, key)
		if type(value) == types.FunctionType:
			return value()
		if os.access(value, os.R_OK):
			return open(value).read()
		raise ValueError, 'Value is not a readable file!'

	I only downloaded Python 2.2 _today_ and already I am using 
the class/type unification features!<0.5 wink>
>  So the value of a key is a text file somewhere on the PC.  And if so,
> how do I instruct Python to open the text file and print into screen
> when the key of the text file is used? Also, is it possible to link a
> value of a Dictionary key into a Python function/procedure?  So, if
> the key is encountered, a way for the functionprocedure to be run.
> Maan