访问以下布局中的属性时出现“列表索引超出范围”错误答案

【问题标题】：'List index is out of range' error for accessing an attribute in the following layout访问以下布局中的属性时出现“列表索引超出范围”错误
【发布时间】：2020-10-10 14:54:32
【问题描述】：

我正在使用 twitter 流 API，但我无法访问 screen_name 属性，因为嵌套的各个层让我有点困惑

这是我尝试过的

results = t.search(q='tuberculosis', count=50)
all_tweets = results['statuses']

for tweet in all_tweets:
        tweetString = tweet["text"]
        name = tweet["entities"]["user_mentions"][0]["screen_name"]
        time = tweet["created_at"]
        df1['Tweet'] = [tweetString]
        df1['Name'] = [name]
        df1['Time'] = [time]
            
        df = df.append(df1)

这是 JSON 布局：

[
  {
    "created_at": "Thu Apr 06 15:28:43 +0000 2017",
    "id": 850007368138018817,
    "id_str": "850007368138018817",
    "text": "RT @TwitterDev: 1/ Today we’re sharing our vision for the future of the Twitter API platform!nalink",
    "truncated": false,
    "entities": {
      "hashtags": [],
      "symbols": [],
      "user_mentions": [
        {
          "screen_name": "TwitterDev",   <------ I want to access this 
          "name": "TwitterDev",
          "id": 2244994945,
          "id_str": "2244994945",
          "indices": [
            3,
            14
          ]
        }
      ],
      "urls": [
        {
          "url": "Link",
          "expanded_url": "https://cards.twitter.com/cards/18ce53wgo4h/3xo1c",
          "display_url": "cards.twitter.com/cards/18ce53wg…",
          "indices": [
            94,
            117
          ]
        }
      ]
    },
    "source": "<a href="http://twitter.com" rel="nofollow">Twitter Web Client</a>",
    "in_reply_to_status_id": null,
    "in_reply_to_status_id_str": null,
    "in_reply_to_user_id": null,
    "in_reply_to_user_id_str": null,
    "in_reply_to_screen_name": null,
    "user": {
      "id": 6253282,
      "id_str": "6253282",
      "name": "Twitter API",
      "screen_name": "twitterapi",
      "location": "San Francisco, CA",
      "description": "The Real Twitter API. I tweet about API changes, service issues and happily answer questions about Twitter and our API. Don't get an answer? It's on my website.",
      "url": "Link",
      "entities": {
        "url": {
          "urls": [
            {
              "url": "Link",
              "expanded_url": "https://dev.twitter.com",
              "display_url": "dev.twitter.com",
              "indices": [
                0,
                22
              ]
            }
          ]
        },
        "description": {
          "urls": []
        }
      },
      "protected": false,
      "followers_count": 6172353,
      "friends_count": 46,......

【问题讨论】：

您是否遇到任何错误？或者当你使用 tweet["entities"]["user_mentions"][0]["screen_name"] 时会发生什么？
是的，我收到了错误list index is out of range

标签： python json twitter twython

【解决方案1】：

userMentions 列表可能为空，因此访问第 0 个索引值可能会出现此错误。

我稍微修改了你的代码。我不确定你在哪里声明了 df1 和 df 之类的变量...但是，请参考我的更改

results = t.search(q='tuberculosis', count=50)
all_tweets = results['statuses']

for tweet in all_tweets:
        tweetString = tweet["text"]
        #name = tweet["entities"]["user_mentions"][0]["screen_name"]
        userMentionList = tweet["entities"]["user_mentions"]
        if len(userMentionList)>0:
            for eachUserMention in userMentionList:
                name = eachUserMention["screen_name"]
                time = tweet["created_at"]
                df1['Tweet'] = [tweetString]
                df1['Name'] = [name]
                df1['Time'] = [time]
                    
                df = df.append(df1)

【讨论】：