在JSON有效負載格式中分配變數值

我正在使用 python 3.6.3a。我想為每個 json 記錄生成有效負載。我正在使用每個變數來訪問記錄。如何each在有效載荷中分配變數值（在這種情況下）？我試過{each}和其他方法，但沒有奏效。

下面的代碼片段。

json_records =  [{"description":"<p>This is scenario1<\/p>","owner":"deb",
                  "priority":"high"},
                 {"description":"<p>This is scenario2<\/p>","owner":"deb",
                  "priority":"medium"}]

json_object = json.loads(json_records)

for each in json_object:
   payload = """
   {
     "subject": "test",
     "fieldValues": [
         {each}
      ]
   }
   """

uj5u.com熱心網友回復：

有兩種方法可以解決這個問題。一種方法是創建一個dict() 物件并根據需要插入鍵，然后json.dumps(object)將其轉換為字串有效負載，如下所示：

import json
json_records = [{"description":"This is scenario1</p>","owner":"deb","priority":"high"}
,{"description":"This is scenario2</p>","owner":"deb","priority":"medium"}]

for obj in json_records:
    payload =  dict()
    payload['subject'] = 'test'
    for key,value in obj.items():
        payload['fieldName'] = {
            key:value
        }
    print(json.dumps(payload))
#{"subject": "test", "fieldName": {"priority": "high"}}
#{"subject": "test", "fieldName": {"priority": "medium"}}

第二種方法是從字串創建文本有效負載，但是如果最后需要一個有效的 JSON，這將需要驗證的后期步驟（類似于try json.loads(payload） - 所以我只使用第一種方法。僅當我有特定要求以某種方式生成有效負載時，我才會使用此方法。

import json
json_records = [{"description":"This is scenario1</p>","owner":"deb","priority":"high"}
,{"description":"This is scenario2</p>","owner":"deb","priority":"medium"}]

# json_object = json.loads(json_records) # json.loads works only on byte-like strings. your object is already in python in this case.

for obj in json_records:
    payload =  """
   {
     "subject": "test",
     "fieldValues": [ 
         %s 
      ]
   }
   """ % (obj["priority"])
    print(payload)
#{
#     "subject": "test",
#     "fieldValues": [ 
#         high 
#      ]
#   }
#   
#
#   {
#     "subject": "test",
#     "fieldValues": [ 
#         medium 
#      ]
#   }
 

uj5u.com熱心網友回復：

您可以創建payload一個Template字串并使用它來將每個 JSON 記錄中的資料放入您想要的格式。括號{}字符在Templates 中沒有特殊含義，這使得它們易于使用。

這樣做將創建一個包含所有內容的字典的有效字串表示。您可以使用該ast.literal_eval()函式將其轉換為實際的 Python 字典資料結構，然后將其轉換為 JSON 字串格式——我認為這是您所追求的最終格式。

rom ast import literal_eval
import json
from string import Template
from textwrap import dedent


json_records = '''[{"description":"<p>This is scenario1<\/p>","owner":"deb",
                    "priority":"high"},
                    {"description":"<p>This is scenario2<\/p>","owner":"deb",
                     "priority":"medium"}]'''

json_object = json.loads(json_records)

payload = Template(dedent("""
    {
      "subject": "test",
      "fieldValues": [
          $each
       ]
    }""")
)

for each in json_object:
    obj = literal_eval(payload.substitute(dict(each=each)))
    print(json.dumps(obj, indent=2))

輸出：

{
  "subject": "test",
  "fieldValues": [
    {
      "description": "<p>This is scenario1</p>",
      "owner": "deb",
      "priority": "high"
    }
  ]
}
{
  "subject": "test",
  "fieldValues": [
    {
      "description": "<p>This is scenario2</p>",
      "owner": "deb",
      "priority": "medium"
    }
  ]
}

標籤：Python json 蟒蛇-3.x

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