Question

Python-如何检查 JSON 中的键是否具有空值？

2020-01-24

5773

python json python-3.x

在 JSON 中，我想检查和统计谁有学位（最高级别，以及什么类型）以及谁没有。虽然统计和检查硕士、博士等学位是可行的，但检查是否存在 null 则不行。

JSON 的一部分

  "id": 125428,
  "Degree": "Master",

不同的候选人：

  ""id": 125589,
  "Degree": null,

不同的候选人：

  "id": 944987,
  "Degree": "PhD"

我的相关代码如下：

mastercounter = 0
phdcounter = 0
nodeegreecounter = 0

for candidate in response["person"]:
    if item["Degree"]:
        if item["Degree"]["key"] == "Master":
            mastercounter = mastercounter + 1
        if item["license"]["key"] == "PhD":
            phdcounter = phdcounter + 1
   if item["Degree"] == None: 
       nodegreecounter = nodegreecounter + 1

我收到的错误是“TypeError：'NoneType' 对象不可下标”

是标识错误，还是代码/我的整个逻辑？

Answer 1

那么使用 if/else 怎么样？

mastercounter = 0
phdcounter = 0
nodeegreecounter = 0

for candidate in response["person"]:
    if item["Degree"]:
        if item["Degree"]["key"] == "Master":
            mastercounter = mastercounter + 1
        if item["license"]["key"] == "PhD":
            phdcounter = phdcounter + 1
    else: 
       nodegreecounter = nodegreecounter + 1

Answer 2

这取决于您的 JSON 是如何组织的。我怀疑响应是一系列人员。像这样：

response = [{"id": "1", "Degree": "Master"}, {"id": "2", "Degree": null}]

因此您应该使用：

for person in response:

您只需要一个人的一个属性（名为“Degree”）。

因此，如果一个人是一系列属性，则代码变为：

for person in response:
    if person["Degree"] is None:
        nodegreecounter = nodegreecounter + 1
    elif person["Degree"] == "Master":
        mastercounter = mastercounter + 1
    elif person["Degree"] == "PhD":
        phdcounter = phdcounter + 1

如果您的 JSON 组织方式不同，您应该在寻求建议之前解释 JSON 结构。

如果您的 JSON 看起来像这样：

{"key11": {"id": "1", "Degree": "Master"}, "key12": {"id": "2", "Degree": null}}

代码可以是：

for key in response:
    if response[key]["Degree"] is None:
        nodegreecounter = nodegreecounter + 1
    elif response[key]["Degree"] == "Master":
        mastercounter = mastercounter + 1
    elif response[key]["Degree"] == "PhD":
        phdcounter = phdcounter + 1

或

for key, person in response.items():
    if person["Degree"] is None:
        nodegreecounter = nodegreecounter + 1
    elif person["Degree"] == "Master":
        mastercounter = mastercounter + 1
    elif person["Degree"] == "PhD":
        phdcounter = phdcounter + 1

Answer 3

正确访问字典键。

mastercounter = 0
phdcounter = 0
nodeegreecounter = 0

for candidate in response["person"]:
    if item["Degree"]:
        if item["Degree"] == "Master":
            mastercounter = mastercounter + 1
        if item["Degree"] == "PhD":
            phdcounter = phdcounter + 1
    else: 
       nodegreecounter = nodegreecounter + 1