python 重载 __hash__ __eq__

__author__ = 'root'
from urlparse import urlparse

class host_news():

    def __init__(self, id, url):
        self.id = id
        urlinfo = urlparse(url)
        self.host = urlinfo.hostname
        self.url = url

    def __init__(self, id, host, url):
        self.id = id
        self.host = host
        self.url = url

    def __eq__(self, other):
        return self.host == other.host

    def __hash__(self):
        return self.host.__hash__()

    def __str__(self):
        return 'id:%s   host:%s url:%s' % (self.id, self.host, self.url)

if __name__ == '__main__':
    o1 = host_news(0, 'www'*2, 'www.1')
    o2 = host_news(0, 'www'*2, '')
    o3 = host_news(1, 'qqq'*2, '')
    print o1 is o2
    print o1 == o2

    t = [o1, o3]
    print o2 in t

# 注释掉__hash__ __eq__ 结果就全是false