using execfile() in class/instance methods

[Wayne Cuddy]

I am attempting to use the execfile() function to "source" a file that  
has valid python code to create a diction object: 
 
bn { 'key' : 'value1', 
        'key2' : 'value2' } 
 
I am issueing this command from a class constructor method and would 
like bn to be bound the class instance.  So in the future I can say: 
        print self.bn['key'] 
 
Is this possible?  I assume I am screwing up the global() and locals()  
arguments to the function which I can say that I don't fully 
understand.  Also is there another better/worse way to do this???just 
so I can see what else is out there.. 
 
Thanks in advance, 
 
Wayne