def _encode_dictionary dictionary content for key in sorted dictionary

def _encode_dictionary(dictionary):
    content=''
    
    for key in sorted(dictionary.keys()):
        if isinstance(key,(StringType,StringTypes)):
            content+=(encode(key)+encode(dictionary[key]))
        else:
            raise InvalidData(key,"dictionary keys must be strings")
        
    
    return 'd%se' %content