具有重复键或无键的Python dict

我在python中有一个类，其中我有一个包含邻居的dict，一个包含21个类实例的列表

pri_list

，但是如果我迭代该邻居，我会得到重复的键或

None

print type(self.neighbors)
print str(self.id) + " " + str(self.neighbors)
print ""
for n in self.neighbors:
    print str(pri_list[n].id) + " " + str(pri_list[n].neighbors)
    pri_list[n].neighbors.update({self.id:self.neighbors[n]})
    print str(pri_list[n].id) + " " + str(pri_list[n].neighbors)

导致

<type 'dict'>
21 {22: 34.348765355132869, 23: 0, 19: 0.049076419727497315, 20: 36.087031068160286}

22 {21: 34.348765355132869, 23: 34.602568871995345, 8: 0.2351466696454737, 17: 0, 20: 0}
22 {21: 34.348765355132869, 23: 34.602568871995345, 8: 0.2351466696454737, 17: 0, 20: 0}
23 {21: 0, 22: 34.602568871995345, 8: 26.643673903936367, 17: 36.80385613689073}
23 {21: 0, 21: 0, 22: 34.602568871995345, 8: 26.643673903936367, 17: 36.80385613689073}
19 {21: 0.049076419727497315, 14: 0, 18: 41.407044987390677, 20: 39.517515427920443}
19 {21: 0.049076419727497315, 14: 0, 18: 41.407044987390677, 20: 39.517515427920443}
20 {21: 36.087031068160286, 22: 0, 18: 0.58414114578772669, 19: 39.517515427920443}
20 {21: 36.087031068160286, 22: 0, 18: 0.58414114578772669, 19: 39.517515427920443}

给出相同的结果

我在两台不同的机器上试过，结果都一样

我做了一个测试示例，其中我将dict中的数据复制到as上

class A:
    neighbors = {}
    id = 0

    def __init__(self,id, neighbors):
        self.id = id
        self.neighbors = neighbors.copy()

if __name__ == "__main__":
    pri_list = [A(i, {})for i in range(0, 19)]

    pri_list.append(A(19, {21: 0.049076419727497315, 14: 0, 18: 41.407044987390677, 20: 39.517515427920443}))
    pri_list.append(A(20, {21: 36.087031068160286, 22: 0, 18: 0.58414114578772669, 19: 39.517515427920443}))
    pri_list.append(A(21, {22: 34.348765355132869, 23: 0, 19: 0.049076419727497315, 20: 36.087031068160286}))
    pri_list.append(A(22, {21: 34.348765355132869, 23: 34.602568871995345, 8: 0.2351466696454737, 17: 0, 20: 0}))
    pri_list.append(A(23, {21: 0, 22: 34.602568871995345, 8: 26.643673903936367, 17: 36.80385613689073}))

    print type(pri_list[21].neighbors)
    print str(pri_list[21].id) + " " + str(pri_list[21].neighbors)
    print ""

    for n in pri_list[21].neighbors:
        print str(pri_list[n].id) + " " + str(pri_list[n].neighbors)
        pri_list[n].neighbors.update({pri_list[21].id:pri_list[21].neighbors[n]})
        print str(pri_list[n].id) + " " + str(pri_list[n].neighbors)

这产生了预期的结果

<type 'dict'>
21 {22: 34.348765355132869, 23: 0, 19: 0.049076419727497315, 20:     36.087031068160286}

22 {8: 0.2351466696454737, 17: 0, 20: 0, 21: 34.348765355132869, 23: 34.602568871995345}
22 {8: 0.2351466696454737, 17: 0, 20: 0, 21: 34.348765355132869, 23: 34.602568871995345}
23 {21: 0, 22: 34.602568871995345, 8: 26.643673903936367, 17: 36.80385613689073}
23 {21: 0, 22: 34.602568871995345, 8: 26.643673903936367, 17: 36.80385613689073}
19 {21: 0.049076419727497315, 14: 0, 18: 41.407044987390677, 20: 39.517515427920443}
19 {21: 0.049076419727497315, 14: 0, 18: 41.407044987390677, 20: 39.517515427920443}
20 {21: 36.087031068160286, 22: 0, 18: 0.58414114578772669, 19: 39.517515427920443}
20 {21: 36.087031068160286, 22: 0, 18: 0.58414114578772669, 19: 39.517515427920443}

21 {22: 34.348765355132869, 23: 0, 19: 0.049076419727497315, 20:     36.087031068160286}
22 {8: 0.2351466696454737, 17: 0, 20: 0, 21: 34.348765355132869, 23: 34.602568871995345}
22 {8: 0.2351466696454737, 17: 0, 20: 0, 21: 34.348765355132869, 23: 34.602568871995345}
23 {21: 0, 22: 34.602568871995345, 8: 26.643673903936367, 17: 36.80385613689073}
23 {21: 0, 22: 34.602568871995345, 8: 26.643673903936367, 17: 36.80385613689073}
19 {21: 0.049076419727497315, 14: 0, 18: 41.407044987390677, 20: 39.517515427920443}
19 {21: 0.049076419727497315, 14: 0, 18: 41.407044987390677, 20: 39.517515427920443}
20 {21: 36.087031068160286, 22: 0, 18: 0.58414114578772669, 19: 39.517515427920443}
20 {21: 36.087031068160286, 22: 0, 18: 0.58414114578772669, 19: 39.517515427920443}

在执行更新后，观察键21如何在

id=23

dict中仅出现一次，并且dict的排列也不同

---

我甚至很难理解在同一个dict中如何出现多个键，根据这一点，这应该是不可能的

您提供的代码的问题是，您在迭代时更新了词典。我不是100%确定这是原因，但一般来说，这是一个坏主意，它确实会导致不可预测的结果。只需复制一份以进行迭代。

循环后，您能否再次打印

打印自己的邻居？我的猜测是没有添加任何内容。旁白：如果
len（poly_line）<0
做过任何事情，那将是非常令人惊讶的。我猜
相邻的
pri_list[23]
的dict中有一个看起来像整数但实际上不是一的键。具体地说，它的
repr
是
“21”
，但它的
散列
不是
散列（21）
。你能试着在pri_列表[23]中运行键的
。邻居：打印（键，键入（键））
？
21
键之一不是整数吗？您是如何在原始代码中生成这些键的？谢谢，这是一个非常好的主意，但不幸的是，输出都是int（21，）（21，）（22，）（8，）（17，）您的代码在迭代字典时会更新字典吗？然后，您是否看到一个键一次、两次或根本没有，这是未定义的，您需要以其他方式进行迭代。我能想到两个，但它们并不相等。
<type 'dict'>
21 {22: 34.348765355132869, 23: 0, 19: 0.049076419727497315, 20:     36.087031068160286}

22 {8: 0.2351466696454737, 17: 0, 20: 0, 21: 34.348765355132869, 23: 34.602568871995345}
22 {8: 0.2351466696454737, 17: 0, 20: 0, 21: 34.348765355132869, 23: 34.602568871995345}
23 {21: 0, 22: 34.602568871995345, 8: 26.643673903936367, 17: 36.80385613689073}
23 {21: 0, 22: 34.602568871995345, 8: 26.643673903936367, 17: 36.80385613689073}
19 {21: 0.049076419727497315, 14: 0, 18: 41.407044987390677, 20: 39.517515427920443}
19 {21: 0.049076419727497315, 14: 0, 18: 41.407044987390677, 20: 39.517515427920443}
20 {21: 36.087031068160286, 22: 0, 18: 0.58414114578772669, 19: 39.517515427920443}
20 {21: 36.087031068160286, 22: 0, 18: 0.58414114578772669, 19: 39.517515427920443}