一尘不染

删除JSON对象中的元素

json

我试图遍历对象列表,从每个对象中删除一个元素。每个对象都是换行符。我试图然后按原样保存新文件,而对象中不包含任何元素。我知道这可能是一个简单的任务,但似乎无法完成这项工作。如果有人可以伸出援手,将不胜感激。谢谢。

{
"business_id": "fNGIbpazjTRdXgwRY_NIXA",
"full_address": "1201 Washington Ave\nCarnegie, PA 15106",
"hours": {
    "Monday": {
        "close": "23:00",
        "open": "11:00"
    },
    "Tuesday": {
        "close": "23:00",
        "open": "11:00"
    },
    "Friday": {
        "close": "23:00",
        "open": "11:00"
    },
    "Wednesday": {
        "close": "23:00",
        "open": "11:00"
    },
    "Thursday": {
        "close": "23:00",
        "open": "11:00"
    },
    "Saturday": {
        "close": "23:00",
        "open": "11:00"
    }
},
"open": true,
"categories": ["Bars", "American (Traditional)", "Nightlife", "Lounges", "Restaurants"],
"city": "Carnegie",
"review_count": 7,
"name": "Rocky's Lounge",
"neighborhoods": [],
"longitude": -80.0849416,
"state": "PA",
"stars": 4.0,
"latitude": 40.3964688,
"attributes": {
    "Alcohol": "full_bar",
    "Noise Level": "average",
    "Music": {
        "dj": false
    },
    "Attire": "casual",
    "Ambience": {
        "romantic": false,
        "intimate": false,
        "touristy": false,
        "hipster": false,
        "divey": false,
        "classy": false,
        "trendy": false,
        "upscale": false,
        "casual": false
    },
    "Good for Kids": true,
    "Wheelchair Accessible": true,
    "Good For Dancing": false,
    "Delivery": false,
    "Dogs Allowed": false,
    "Coat Check": false,
    "Smoking": "no",
    "Accepts Credit Cards": true,
    "Take-out": true,
    "Price Range": 1,
    "Outdoor Seating": false,
    "Takes Reservations": false,
    "Waiter Service": true,
    "Wi-Fi": "free",
    "Caters": false,
    "Good For": {
        "dessert": false,
        "latenight": false,
        "lunch": false,
        "dinner": false,
        "brunch": false,
        "breakfast": false
    },
    "Parking": {
        "garage": false,
        "street": false,
        "validated": false,
        "lot": true,
        "valet": false
    },
    "Has TV": true,
    "Good For Groups": true
},
"type": "business"

}

我需要删除小时元素中包含的信息,但是信息并不总是相同的。有些包含全天,有些仅包含一两天的信息。我尝试使用的代码是Pyton,我整天都在搜索该代码以解决问题。我对Python不太熟练。任何帮助,将不胜感激。

import json

with open('data.json') as data_file:
data = json.load(data_file)
for element in data: 
        del element['hours']

对不起,只是添加我在运行代码时遇到的错误是TypeError:“ unicode”对象不支持项目删除


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2020-07-27

共1个答案

一尘不染

假设您要覆盖相同的文件:

import json

with open('data.json', 'r') as data_file:
    data = json.load(data_file)

for element in data:
    element.pop('hours', None)

with open('data.json', 'w') as data_file:
    data = json.dump(data, data_file)

dict.pop(<key>, not_found=None)如果我了解您的要求,那么您可能正在寻找。因为hours如果存在,它将删除密钥,如果不存在,它将不会失败。

但是我不确定我是否理解小时键是否包含几天对您有什么影响,因为您只想摆脱整个键/值对,对吗?

现在,如果您确实要使用del而不是pop,请按以下步骤使代码正常工作:

import json

with open('data.json') as data_file:
    data = json.load(data_file)

for element in data:
    if 'hours' in element:
        del element['hours']

with open('data.json', 'w') as data_file:
    data = json.dump(data, data_file)

编辑 因此,如您所见,我添加了代码以将数据写回到文件中。如果要将其写入另一个文件,只需在第二个open语句中更改文件名。

您可能已经注意到,我不得不更改了缩进,以便在数据清理阶段关闭文件,并在最后将其覆盖。

with是所谓的上下文管理器,它提供的任何内容(此处为data_file文件描述符)
在该上下文中可用。这意味着,一旦with块的缩进结束,文件就会关闭并且上下文也将结束,文件描述符也变得无效/过时。

如果不这样做,您将无法以写入模式打开文件并获得要写入的新文件描述符。

我希望已经足够清楚了…

第二编辑

这次,您似乎显然需要执行以下操作:

with open('dest_file.json', 'w') as dest_file:
    with open('source_file.json', 'r') as source_file:
        for line in source_file:
            element = json.loads(line.strip())
            if 'hours' in element:
                del element['hours']
            dest_file.write(json.dumps(element))
2020-07-27