def asDict( self ):
        """
        Returns the named parse results as a nested dictionary.

        Example::
            integer = Word(nums)
            date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
            
            result = date_str.parseString('12/31/1999')
            print(type(result), repr(result)) # -> <class 'pyparsing.ParseResults'> (['12', '/', '31', '/', '1999'], {'day': [('1999', 4)], 'year': [('12', 0)], 'month': [('31', 2)]})
            
            result_dict = result.asDict()
            print(type(result_dict), repr(result_dict)) # -> <class 'dict'> {'day': '1999', 'year': '12', 'month': '31'}

            # even though a ParseResults supports dict-like access, sometime you just need to have a dict
            import json
            print(json.dumps(result)) # -> Exception: TypeError: ... is not JSON serializable
            print(json.dumps(result.asDict())) # -> {"month": "31", "day": "1999", "year": "12"}
        """
        if PY_3:
            item_fn = self.items
        else:
            item_fn = self.iteritems
            
        def toItem(obj):
            if isinstance(obj, ParseResults):
                if obj.haskeys():
                    return obj.asDict()
                else:
                    return [toItem(v) for v in obj]
            else:
                return obj
                
        return dict((k,toItem(v)) for k,v in item_fn())

        Returns the named parse results as a nested dictionary.

        Example::
            integer = Word(nums)
            date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
            
            result = date_str.parseString('12/31/1999')
            print(type(result), repr(result)) # -> <class 'pyparsing.ParseResults'> (['12', '/', '31', '/', '1999'], {'day': [('1999', 4)], 'year': [('12', 0)], 'month': [('31', 2)]})
            
            result_dict = result.asDict()
            print(type(result_dict), repr(result_dict)) # -> <class 'dict'> {'day': '1999', 'year': '12', 'month': '31'}

            # even though a ParseResults supports dict-like access, sometime you just need to have a dict
            import json
            print(json.dumps(result)) # -> Exception: TypeError: ... is not JSON serializable
            print(json.dumps(result.asDict())) # -> {"month": "31", "day": "1999", "year": "12"}
        
src/pkg_resources/_vendor/pyparsing.py