python json 无法哈希类型 'list

Question

我有一段代码，它用来把JSON数据提交到服务器，但出现了一个错误，提示“不可哈希的类型列表”。

hcatalog_nodes =["idh30-1.srv.acent.net.uk","idh30-2.srv.acent.net.uk","idh30-3.srv.acent.net.uk"]
for node in hcatalog_nodes:
    data = json.dumps({[
                            {
                                "rolename": "HCatalog",
                                "hostname": node
                            }

                        ]})
    request = urllib2.Request("https://192.168.0.76:9443/restapi/acent/api/v2/cluster/"+cluster_name+"/services/hbase/roles")
    base64string = base64.encodestring('%s:%s' % ("admin", "admin")).replace('\n', '')
    request.add_header("Authorization", "Basic %s" % base64string)
    print "setting up HBase roles on node %s " % (node)
    result = urllib2.urlopen(request,data)
    print result.read()

错误：

Traceback (most recent call last):
  File "/home/kshk/PycharmProjects/intelIDH/autoIDH.py", line 287, in <module>
    main()
  File "/home/kshk/PycharmProjects/intelIDH/autoIDH.py", line 278, in main
    add_hcatalogRoles()
  File "/home/kshk/PycharmProjects/intelIDH/autoIDH.py", line 147, in add_hcatalogRoles
    "hostname": node
TypeError: unhashable type: 'list'

Process finished with exit code 1

有没有人知道我该怎么设置JSON请求中“node”的值呢？

Answer 1

问题出在 json.dumps() 这一行：

data = json.dumps({[{"rolename": "HCatalog", "hostname": node}]})

这里其实是在尝试创建一个只有一个列表元素的集合。但在Python中，列表不能作为集合的元素。

---

你可能是想创建一个字典，然后把它传给 json.dumps()：

data = json.dumps({"rolename": "HCatalog", "hostname": node})