遍历JSON [Python]

Question

我正在用python阅读以下JSON文件：

    {
  "name": "Property",
  "base": "PersistedModel",
  "idInjection": true,
  "options": {
    "validateUpsert": true
  },
  "properties": {
    "uuid": {
      "type": "string"
    },
    "userID": {
      "type": "number"
    },
    "address": {
      "type": "string"
    },
    "price": {
      "type": "number"
    },
    "lastUpdated": {
      "type": "string"
    }
  },
  "validations": [],
  "relations": {
    "rooms": {
      "type": "hasMany",
      "model": "Room",
      "foreignKey": "id"
    },
    "addedByUser": {
      "type": "hasMany",
      "model": "User_ESPC",
      "foreignKey": "id"
    }
  },
  "acls": [],
  "methods": {}
}

我正在尝试读取properties并获取properties的名称（例如“ uuid”），对于每个名称，我想读取对象的类型。 到目前为止，我的代码列出了所有类似的属性：

Property name: price
Property name: userID
Property name: uuid
Property name: lastUpdated
Property name: address

这样做的代码是：

import json

#json_file='a.json'
json_file='common/models/property.json'
with open(json_file, 'r') as json_data:
    data = json.load(json_data)


propertyName = data["name"]
properties = data["properties"]

# print (properties)

for property in properties:
    print ('Property name: ' + property)
    # propertyType = property["type"]
    # print (propertyType)

问题是，当我取消注释应该获得属性对象类型的底部两行时，出现错误：

Property name: price
Traceback (most recent call last):
File "exportPropertyToAndroid.py", line 19, in <module>
propertyType = property["type"]
TypeError: string indices must be integers

Answer 1

遍历字典会产生其键。 properties是一个字典：

properties = data["properties"]

当您遍历以下内容时：

for property in properties:
    print ('Property name: ' + property)
    # propertyType = property["type"]
    # print (propertyType)

property依次引用每个键。 因为您的字典代表JSON数据，所以键是字符串，并且错误很容易说明。 property["type"]试图从索引"type"处的字符串中获取字符。

相反，您应该使用key property从字典中获取其他值：

for property in properties:
    print ('Property name: ' + property)
    propertyType = properties[property]["type"]
    print(propertyType)

或遍历键和值：

for property, value in properties.items():
    print ('Property name: ' + property)
    propertyType = value["type"]
    print(propertyType)