在json中从多个值中获取值

Question

我尝试从json字段中的多个值中获取一个值。我使用这个for循环从json文件中获取数据：

for i in data['issues']:
x = [i]
for j in x:
    pprint(j['fields']['assignee'])

这就是我的回报：

{'active': True,
 'avatarUrls': {'16x16': 'link',
                '24x24': 'link',
                '32x32': 'link',
                '48x48': 'link'},
 'displayName': 'First name, Last name',
 'emailAddress': 'name.namek@mail.com',
 'name': 'Name',
 'self': 'link'}

我试图使用其中一个值，例如我想获得＆＃39; displayName＆＃39;

的价值

pprint(j['fields']['assignee'][0])

但是在python IDE中我遇到了这个错误：

TypeError: 'NoneType' object is not subscriptable

好的更具体一点我想从这个json得到例如值displayName，如果我在这里粘贴一个完整的json结构，它可能会更容易

{
"expand": "schema,names",
"startAt": 0,
"maxResults": 50,
"total": 4,
"issues": [
    {
        "expand": "editmeta,renderedFields,transitions,changelog,operations",
        "id": "682884",
        "self": "https://jira.sabre.com/rest/api/2/issue/682884",
        "key": "ENG-664",
        "fields": {
            "data": "data",
            "assignee": {
                "self": "link",
                "name": "First name Last name",
                "emailAddress": "ame.namek@mail.com",
                "avatarUrls": {
                    "16x16": "link",
                    "24x24": "link",
                    "32x32": "link",
                    "48x48": "link"
                },
                "displayName": "First name Last name",
                "active": true
            }
        }
    },
    {
        "expand": "editmeta,renderedFields,transitions,changelog,operations",
        "id": "682884",
        "self": "https://jira.sabre.com/rest/api/2/issue/682884",
        "key": "ENG-664",
        "fields": {
            "data": "data",
            "assignee": {
                "self": "link",
                "name": "First name Last name",
                "emailAddress": "ame.namek@mail.com",
                "avatarUrls": {
                    "16x16": "link",
                    "24x24": "link",
                    "32x32": "link",
                    "48x48": "link"
                },
                "displayName": "First name Last name",
                "active": true
            }
        }
    },
    {
        "expand": "editmeta,renderedFields,transitions,changelog,operations",
        "id": "682884",
        "self": "https://jira.sabre.com/rest/api/2/issue/682884",
        "key": "ENG-664",
        "fields": {
            "data": "data",
            "assignee": {
                "self": "link",
                "name": "First name Last name",
                "emailAddress": "ame.namek@mail.com",
                "avatarUrls": {
                    "16x16": "link",
                    "24x24": "link",
                    "32x32": "link",
                    "48x48": "link"
                },
                "displayName": "First name Last name",
                "active": true
            }
        }
    },
    {
        "expand": "editmeta,renderedFields,transitions,changelog,operations",
        "id": "682884",
        "self": "https://jira.sabre.com/rest/api/2/issue/682884",
        "key": "ENG-664",
        "fields": {
            "data": "data",
            "assignee": {
                "self": "link",
                "name": "First name Last name",
                "emailAddress": "ame.namek@mail.com",
                "avatarUrls": {
                    "16x16": "link",
                    "24x24": "link",
                    "32x32": "link",
                    "48x48": "link"
                },
                "displayName": "First name Last name",
                "active": true
            }
        }
    }
]}