遇到python错误<generator object <genexpr>

Question

当我跑步时a = ["I","love","you"]a = {(word) for word in a}print a我得到这个结果set(['I', 'you', 'love'])这就是我的期望。但是当我跑步时a = ["I","love","you"]a = {((word) for word in c)for c in a}print a我得到一些意想不到的结果：set([<generator object <genexpr> at 0x1004d5280>, <generator object <genexpr> at 0x1004d5320>, <generator object <genexpr> at 0x1004d5370>])我期望的是set(['e','I','u','o','v','l','y')谁能告诉我导致这个问题的原因？