Question

我有一个包含100个Cluster对象的字典，这些集群有几个Member对象，我需要将它们添加到它们所属的集群中，我的问题是每个成员都被添加到每个集群中，我无法找到为什么。这是代码

self.clusters = {}

with open('/tmp/numpy_dumps/kmeansInput.txt.cluster_centres') as f:
    for line in f:
        cluster = Cluster(line)
        self.clusters[cluster.id] = cluster

with open('/tmp/numpy_dumps/kmeansInput.txt.membership') as f:
    for line in f:
        member = Member(line, self.reps)
        self.clusters[member.clusterId].members[member.imageId] = member

for id, cluster  in self.clusters.items():
    print(cluster)
    print(cluster.members)
    print('cluster {} has {} members'.format(id, len(cluster.members)))

输出告诉我每个群集都有所有成员

Answer 1

问题非常肯定在Cluster课程中，你没有在你的片段中发帖。这是一个疯狂的猜测，但这种行为是共享属性的典型特征，无论是类属性还是可变的默认参数。如果您的Cluster类看起来像下面的其中一个片段，那么就不会再看了：

# class attributes:

class Cluster(object):
    members = {} # this will be shared by all instances

# solution:

class Cluster(object):
    def __init__(self):
        self.members = {} # this will be per instance



# default mutable argument:

class Cluster(object):
    def __init__(self, members={}):
        # this one is well known gotcha:
        # the default for the `members` arg is eval'd only once
        # so all instances created without an explicit
        # `members` arg will share the same `members` dict
        self.members = members

# solution:

class Cluster(object):
    def __init__(self, members=None):
        if members is None:
            members = {}
        self.members = members

将元素添加到字典

1 个答案: