即使存在密钥，也会遇到KeyError

Question

dir = {"sample":[
{ "key1":"data1" }

,
{ "key1":"data2" }

,
{ "key2":"data3" }

,
{ "key2":"data4" }
]
}

使用我的代码：

listKey1 = []
listKey2 = []
with open(dir) as json_file:
   data = json.load(json_file)
   for p in data['sample']:

        key1data = p['key1']
        print("key1: " + key1data)
        listKey1.append(key1data)
      
        key2data = p['key2']
        print("key2: " + key2data)
        listKey2.append(key2data)
            

我试图将key1和key2键下的数据存储到listKey1和listKey2中，但我得到了错误：

  KeyError: 'key1'
  KeyError: 'key2'

正如我们在我的文件中看到的，key1和key2都存在

Answer 1

您可以迭代元素，通过key进行比较，并相应地存储数据：

dd = {
      "sample":
        [
            { "key1":"data1" },
            { "key1":"data2" },
            { "key2":"data3" },
            { "key2":"data4" }
        ]
    }

key1data = []
key2data = []
for elem in dd['sample']:
    for key, val in elem.items():
        if key == "key1":
            key1data.append(elem.get("key1"))
        else:
            key2data.append(elem.get("key2"))

print(key1data)
print(key2data)

输出：

['data1', 'data2']                                                                                                                                                           
['data3', 'data4']