python之生成器与迭代器专题[持续整理总结]

1.类里面的__iter__

class NodeIterator(object):
    index  = 0
    def __init__(self, nodes):
        self.nodes  =  nodes;
    def next(self):
        if self.index  >  len(self.nodes):
            raise StopIteration()
        self.index += 1
        return self.nodes[self.index-1]

class Node():
    nodes  =  []
    def __init__(self):
        nodes  =  ["a", "b", 1, 2]
        for dataset in nodes:
            self.nodes.append(dataset)

    def __iter__(self):
        return NodeIterator(self.nodes)

o = Node()
for i in o:
    print i

这个方法可以调用一个实现next方法的迭代器类哦。