为我的自定义迭代器实现iteritems函数？

Question

以下程序的目标是学习python生成器和迭代器实现，以便理解python魔术方法。在

我无法实现iteritems()函数。另外，我想知道我是在正确的方向上，还是在概念上理解了python魔术方法。在

import random

class Random(object):
    """ generate randomised int of specified length --> [r1, r2, r3....] """

    def __init__(self, length = 1, rand_range = 100):
        self.index = 0
        self.generated_range = []
        self.length = length if str(length).isdigit() else 1
        self.rand_range = rand_range if str(rand_range).isdigit() else 100

    def __iter__(self): return self

    def next(self):
        if self.index < self.length:
            item = random.randrange(0, self.rand_range)
            self.generated_range.append(item)
            self.index += 1
            return item
        raise StopIteration

    def __eq__(self, obj):
        if self.length == obj.length and self.rand_range == obj.rand_range:
            return True
        return False

    def __len__(self):
        return self.length

    def __contains__(self, item):
        if not self.index == self.length:
            while self.next(): continue
        if item in self.generated_range:
            return True
        return False

    def __getitem__(self, key):
        if key in self.generated_range:
            return key * 100
        raise KeyError

    def __setitem__(self, key, value):
        raise NotImplemented

    def __delitem__(self, key):
        raise NotImplemented

    def iteritems(self):
        if not self.index == self.length:
            while self.next(): continue
        for item in self.generated_range:
            yield item

if __name__ == '__main__':
    r1 = Random(10)
    print [ r for r in r1]
    print 10 in r1
    r2 = Random(20)
    print r2.iteritems()

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Answer 1

iteritems应该为字典返回（key，val）对序列，因此我认为它不适合您的类。如果您创建了UserDict的子代，那么可能需要重写它。在

如果确实重写iteritems，那么应该通过生成键、值对来实现。在

编程错误：

def iteritems(self):
    return iter([(x[0], x) for x in "alpha bravo charlie".split()])