'Return a human-readable representation.
>>> str(N[\'dog\'])
\'dog(n.)\''

def __str__(self):

    abbrs = {NOUN: 'n.', VERB: 'v.', ADJECTIVE: 'adj.', ADVERB: 'adv.'}
    return (((self.form + '(') + abbrs[self.pos]) + ')')
