Python-将json文件写入字典列表

Question

我正在根据从 url 中提取的信息编写一个 json 文件。如何在单独的行上打印字典的每个元素？

这是我当前的代码：

dct=[{"name": name,
        "cuisine": cuisine,
        "price-range": price,
        "address": address,
        "rating": rating,
        "reviews": score,
        "district": district,
        "url": link
        }]

    with open('openrice_data.json', 'a') as file:
        file.write(json.dumps(dct))

例如，它当前打印如下：

[{"cuisine": ["Japanese", "Hot Pot", "Buffet"], "rating": [3.5], "address": [22.3825, 114.1901], "url": ["https://www.openrice.com/en/hongkong/r-wagyu-more-sha-tin-japanese-hot-pot-r172321"], "reviews": [35, 17, 8], "name": "Wagyu More", "price-range": ["$101-200"], "district": ["Sha Tin"]}]

我希望它像这样打印：

[
{"name": "Chan Kun Kee",
"cuisine": ["Guang Dong", "Dai Pai Dong"],
"price-range": "$51-100",
"address": [22.3884, 114.1958], 
"rating": 3.5,
"reviews": [216, 95, 38],
"district": "Shatin",
"url": "www.openrice.com/en/hongkong/r-chan-kun-kee-sha-tin-guangdong-r7918"
}
]

Answer 1

更新 实际上，您拥有的是一个字典列表。当您想添加更多元素时，您需要删除字典周围的[]。

要解决您想要使用 indent=0 的特定问题。也可以考虑直接使用json.dump。

import json

l=[]

dct={"name": 'name',
    "cuisine": 'cuisine',
    "price-range": 'price',
    "address": 'address',
    "rating": 'rating',
    "reviews": 'score',
    "district": 'district',
    "url": 'link'
    }

l.append(dct)

with open('openrice_data.json', 'w') as file:
    json.dump(l,file,indent=0)

输出：

[
{
"name": "name",
"cuisine": "cuisine",
"price-range": "price",
"address": "address",
"rating": "rating",
"reviews": "score",
"district": "district",
"url": "link"
}
]

继续

要添加更多元素，您需要这样做：

# Load json to list
with open('openrice_data.json') as f:
    l = json.load(f)

# A new dict    
dct2={"name": 'name',
    "cuisine": 'cuisine',
    "price-range": 'price',
    "address": 'address',
    "rating": 'rating',
    "reviews": 'score',
    "district": 'district',
    "url": 'link'
    }

# Append new dict
l.append(dct2)


with open('openrice_data.json', 'w') as file:
    json.dump(l,file,indent=0)

输出现在包含一个包含 2 个字典的列表。

[
{
"name": "name",
"cuisine": "cuisine",
"price-range": "price",
"address": "address",
"rating": "rating",
"reviews": "score",
"district": "district",
"url": "link"
},
{
"name": "name",
"cuisine": "cuisine",
"price-range": "price",
"address": "address",
"rating": "rating",
"reviews": "score",
"district": "district",
"url": "link"
}
]

Answer 2

不要使用json，pprint 非常适合这项工作。

from pprint import pprint

obj = [{"cuisine": ["Japanese", "Hot Pot", "Buffet"], "rating": [3.5], "address": [22.3825, 114.1901], "url": ["https://www.openrice.com/en/hongkong/r-wagyu-more-sha-tin-japanese-hot-pot-r172321"], "reviews": [35, 17, 8], "name": "Wagyu More", "price-range": ["$101-200"], "district": ["Sha Tin"]}]
with open('dumpfile.json', 'w+') as f:
    pprint(obj, f)

有一些自定义参数，请查看文档了解更多详细信息： https://docs.python.org/3/library/pprint.html

Answer 3

使用漂亮的打印机：

import pprint
pp = pprint.PrettyPrinter(indent=4)
pp.pprint(dct)

另外：您当前正在将 dict 放入列表中。 [] 是一个列表 {} 是 python 中的一个字典。 通过放置 [{}] 您将 dict 放入列表中。只需删除 []。

Answer 4

其他人评论过使用pprint，但我想补充一点，pprint 会在您的字典中打印 Python 值的表示形式。它们并不总是与其对应的 JSON 相同，例如：

>>> from pprint import pprint
>>> d1 = {"value": None}
>>> pprint(d1)
{'value': None}

（这里正确的JSON序列化是{"value": null}

对于这些类型的值，更好的选择是使用json.dump 或json.dumps。您可以使用indent 参数使其每个元素打印一行。请注意，这也会将每个列表元素打印到它们单独的行中（因此您不会准确地得到每个 JSON 键的一行）：

>>> d2 = [
... {"name": "Chan Kun Kee",
... "cuisine": ["Guang Dong", "Dai Pai Dong"],
... "price-range": "$51-100",
... "address": [22.3884, 114.1958], 
... "rating": 3.5,
... "reviews": [216, 95, 38],
... "district": "Shatin",
... "url": "www.openrice.com/en/hongkong/r-chan-kun-kee-sha-tin-guangdong-r7918"
... }
... ]
>>> print(json.dumps(d2, indent=2))
[
  {
    "name": "Chan Kun Kee",
    "cuisine": [
      "Guang Dong",
      "Dai Pai Dong"
    ],
    "price-range": "$51-100",
    "address": [
      22.3884,
      114.1958
    ],
    "rating": 3.5,
    "reviews": [
      216,
      95,
      38
    ],
    "district": "Shatin",
    "url": "www.openrice.com/en/hongkong/r-chan-kun-kee-sha-tin-guangdong-r7918"
  }
]

但至少可以保证您始终获得正确的 JSON。此外，您还可以使用自己的 JSON encoder 扩展行为。例如，这允许您将 Python datetime 对象序列化为 JSON 字符串。