def buildKey(ids, dataLine):
    """
    Concatenate a set of fields together to build an overall key

    This is a simple approach to determining k-anonymity, in which all
    of the fields of interest are concatenated as a single key. The 
    ids coming in should be a list of indexes into the fields in the dataLine.
    These will be concatenated in order to form a new key. Note that this 
    currently assumes that all of the data fields are strings. 

    """
    retKey = ''
    for i in ids:
        retKey += dataLine[i]
        
    return retKey