Json 文件到字典

Question

我正在使用yelp dataset，我想将评论 json 文件解析为字典。我尝试将其加载到 pandas DataFrame 上，然后创建字典，但由于文件太大，因此非常耗时。我只想保留 user_id 和 stars 值。 json文件的一行是这样的：

{
    "votes": {
        "funny": 0, "useful": 2, "cool": 1},
    "user_id": "Xqd0DzHaiyRqVH3WRG7hzg",
    "review_id": "15SdjuK7DmYqUAj6rjGowg", "stars": 5, "date": "2007-05-17",
    "text": (
        "dr. goldberg offers everything i look for in a general practitioner.  "
        "he's nice and easy to talk to without being patronizing; he's always on "
        "time in seeing his patients; he's affiliated with a top-notch hospital (nyu) "
        "which my parents have explained to me is very important in case something "
        "happens and you need surgery; and you can get referrals to see specialists "
        "without having to see him first.  really, what more do you need?  i'm "
        "sitting here trying to think of any complaints i have about him, but i'm "
        "really drawing a blank."
    ),
    "type": "review", "business_id": "vcNAWiLM4dR7D2nwwJ7nCA"
}

我如何遍历每个“字段”（因为缺少更好的词）？到目前为止，我只能遍历每一行。

编辑

根据要求的熊猫代码：

读取 json

with open('yelp_academic_dataset_review.json') as f:
    df = pd.DataFrame(json.loads(line) for line in f)

创建字典

dict = {} 

for i, row in df.iterrows():
   business_id = row['business_id']
   user_id = row['user_id']
   rating = row['stars']
   key = (business_id, user_id)
   dict[key] = rating

Answer 1

您无需将其读入 DataFrame。 json.load() 返回一个字典。例如：

sample.json

{
“投票”：{
“有趣”：0，
“有用”：2，
“酷”：1
},
"user_id": "Xqd0DzHaiyRqVH3WRG7hzg",
"review_id": "15SdjuK7DmYqUAj6rjGowg",
“星星”：5，
"日期": "2007-05-17",
“text”：“goldberg 博士提供了我在全科医生中寻找的一切。他很好，很容易与人交谈，而且不会居高临下；他总是准时看病；他隶属于一流的医院 (nyu)，该医院我的父母已经向我解释了这非常重要，以防万一发生了什么事，你需要手术；而且你可以得到转介去看专科医生，而不必先去看他。真的，你还需要什么？我坐在这里想我对他有任何抱怨，但我真的是一片空白。",
“类型”：“评论”，
“business_id”：“vcNAWiLM4dR7D2nwwJ7nCA”
}

read_json.py

import json

with open('sample.json', 'r') as fh:
    result_dict = json.load(fh)

print(result_dict['user_id'])
print(result_dict['stars'])

输出

Xqd0DzHaiyRqVH3WRG7hzg
5

使用该输出，您可以轻松创建 DataFrame。

关于将 json 解析为 SO 上的流有几个很好的讨论，但要点是它本身是不可能的，尽管一些工具似乎在尝试它。

为了让您的代码保持简单且依赖最少，您可能会看看将 json 目录读入字典是否足够改进。