如何在 .txt 文件中的 JSON 对象之间添加逗号，然后在 Python 中将其转换为 JSON 数组

Question

我正在读取一个包含 JSON 对象的 txt 文件，其中的对象没有用逗号分隔。我想在 json 对象之间添加逗号，并将它们全部放入 JSON 列表或数组中。

我尝试过 JSON.loads，但收到 JSON 解码错误。所以我意识到我应该在 .txt 文件中存在的不同对象之间添加逗号

以下是.txt中文件内容的示例

{
    "@mdate": "2011-01-11",
    "@key": "journals/acta/Saxena96",
    "author": {
        "ftail": "\n",
        "ftext": "Sanjeev Saxena"
    },
    "title": {
        "ftail": "\n",
        "ftext": "Parallel Integer Sorting and Simulation Amongst CRCW Models."
    },
    "pages": {
        "ftail": "\n",
        "ftext": "607-619"
    },
    "year": {
        "ftail": "\n",
        "ftext": "1996"
    },
    "volume": {
        "ftail": "\n",
        "ftext": "33"
    },
    "journal": {
        "ftail": "\n",
        "ftext": "Acta Inf."
    },
    "number": {
        "ftail": "\n",
        "ftext": "7"
    },
    "url": {
        "ftail": "\n",
        "ftext": "db/journals/acta/acta33.htmlfSaxena96"
    },
    "ee": {
        "ftail": "\n",
        "ftext": "http://dx.doi.org/10.1007/BF03036466"
    },
    "ftail": "\n",
    "ftext": "\n"
}{
    "@mdate": "2011-01-11",
    "@key": "journals/acta/Simon83",
    "author": {
        "ftail": "\n",
        "ftext": "Hans-Ulrich Simon"
    },
    "title": {
        "ftail": "\n",
        "ftext": "Pattern Matching in Trees and Nets."
    },
    "pages": {
        "ftail": "\n",
        "ftext": "227-248"
    },
    "year": {
        "ftail": "\n",
        "ftext": "1983"
    },
    "volume": {
        "ftail": "\n",
        "ftext": "20"
    },
    "journal": {
        "ftail": "\n",
        "ftext": "Acta Inf."
    },
    "url": {
        "ftail": "\n",
        "ftext": "db/journals/acta/acta20.htmlfSimon83"
    },
    "ee": {
        "ftail": "\n",
        "ftext": "http://dx.doi.org/10.1007/BF01257084"
    },
    "ftail": "\n",
    "ftext": "\n"
}

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预期结果：

''''''''''''''''''''''''''''''''''

[
{
    "@mdate": "2011-01-11",
    "@key": "journals/acta/Saxena96",
    "author": {
        "ftail": "\n",
        "ftext": "Sanjeev Saxena"
    },
    "title": {
        "ftail": "\n",
        "ftext": "Parallel Integer Sorting and Simulation Amongst CRCW Models."
    },
    "pages": {
        "ftail": "\n",
        "ftext": "607-619"
    },
    "year": {
        "ftail": "\n",
        "ftext": "1996"
    },
    "volume": {
        "ftail": "\n",
        "ftext": "33"
    },
    "journal": {
        "ftail": "\n",
        "ftext": "Acta Inf."
    },
    "number": {
        "ftail": "\n",
        "ftext": "7"
    },
    "url": {
        "ftail": "\n",
        "ftext": "db/journals/acta/acta33.htmlfSaxena96"
    },
    "ee": {
        "ftail": "\n",
        "ftext": "http://dx.doi.org/10.1007/BF03036466"
    },
    "ftail": "\n",
    "ftext": "\n"
},
{
    "@mdate": "2011-01-11",
    "@key": "journals/acta/Simon83",
    "author": {
        "ftail": "\n",
        "ftext": "Hans-Ulrich Simon"
    },
    "title": {
        "ftail": "\n",
        "ftext": "Pattern Matching in Trees and Nets."
    },
    "pages": {
        "ftail": "\n",
        "ftext": "227-248"
    },
    "year": {
        "ftail": "\n",
        "ftext": "1983"
    },
    "volume": {
        "ftail": "\n",
        "ftext": "20"
    },
    "journal": {
        "ftail": "\n",
        "ftext": "Acta Inf."
    },
    "url": {
        "ftail": "\n",
        "ftext": "db/journals/acta/acta20.htmlfSimon83"
    },
    "ee": {
        "ftail": "\n",
        "ftext": "http://dx.doi.org/10.1007/BF01257084"
    },
    "ftail": "\n",
    "ftext": "\n"
}
]

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Answer 1

您可以使用 reqexp 在对象之间添加逗号：

import re

with open('name.txt', 'r') as input, open('out.txt', 'w') as output:
    output.write("[\n")
    for line in input:
        line = re.sub('}{', '},{', line)
        output.write('    '+line)
    output.write("]\n")

Answer 2

如果您始终可以保证您的 JSON 将按照您的示例进行格式化，即新的 JSON 对象从最后一个结束的同一行开始并且没有缩进，您只需将 JSON 读入一个缓冲区，直到遇到这样的行，然后发送缓冲区以进行 JSON 解析 - 冲洗并重复：

import json

parsed = []  # a list to hold individually parsed JSON objects
with open('path/to/your.json') as f:
    buffer = ''
    for line in f:
        if line[0] == '}':  # end of the current JSON object
            parsed.append(json.loads(buffer + '}'))
            buffer = line[1:]
        else:
            buffer += line

print(json.dumps(parsed, indent=2))  # just to make sure it all went well

这会产生：

[
  {
    "@mdate": "2011-01-11",
    "@key": "journals/acta/Saxena96",
    "author": {
      "ftail": "\n",
      "ftext": "Sanjeev Saxena"
    },
    "title": {
      "ftail": "\n",
      "ftext": "Parallel Integer Sorting and Simulation Amongst CRCW Models."
    },
    "pages": {
      "ftail": "\n",
      "ftext": "607-619"
    },
    "year": {
      "ftail": "\n",
      "ftext": "1996"
    },
    "volume": {
      "ftail": "\n",
      "ftext": "33"
    },
    "journal": {
      "ftail": "\n",
      "ftext": "Acta Inf."
    },
    "number": {
      "ftail": "\n",
      "ftext": "7"
    },
    "url": {
      "ftail": "\n",
      "ftext": "db/journals/acta/acta33.htmlfSaxena96"
    },
    "ee": {
      "ftail": "\n",
      "ftext": "http://dx.doi.org/10.1007/BF03036466"
    },
    "ftail": "\n",
    "ftext": "\n"
  },
  {
    "@mdate": "2011-01-11",
    "@key": "journals/acta/Simon83",
    "author": {
      "ftail": "\n",
      "ftext": "Hans-Ulrich Simon"
    },
    "title": {
      "ftail": "\n",
      "ftext": "Pattern Matching in Trees and Nets."
    },
    "pages": {
      "ftail": "\n",
      "ftext": "227-248"
    },
    "year": {
      "ftail": "\n",
      "ftext": "1983"
    },
    "volume": {
      "ftail": "\n",
      "ftext": "20"
    },
    "journal": {
      "ftail": "\n",
      "ftext": "Acta Inf."
    },
    "url": {
      "ftail": "\n",
      "ftext": "db/journals/acta/acta20.htmlfSimon83"
    },
    "ee": {
      "ftail": "\n",
      "ftext": "http://dx.doi.org/10.1007/BF01257084"
    },
    "ftail": "\n",
    "ftext": "\n"
  }
]

如果您的情况不是很明确（即您无法预测格式），您可以尝试一些基于迭代/事件的 JSON 解析器（例如ijson），它们能够告诉您一次'root' 对象已关闭，因此您可以将已解析的 JSON 对象“拆分”成一个序列。

更新：再想一想，除了内置的 json 模块之外，您不需要任何东西，即使您的连接 JSON 没有正确或缩进 - 您可以使用 @ 987654322@（及其未记录的第二个参数）遍历您的数据并以迭代方式查找有效的 JSON 结构，直到您遍历整个文件（或遇到错误）。例如：

import json

parser = json.JSONDecoder()
parsed = []  # a list to hold individually parsed JSON structures
with open('test.json') as f:
    data = f.read()
head = 0  # hold the current position as we parse
while True:
    head = (data.find('{', head) + 1 or data.find('[', head) + 1) - 1
    try:
        struct, head = parser.raw_decode(data, head)
        parsed.append(struct)
    except (ValueError, json.JSONDecodeError):  # no more valid JSON structures
        break

print(json.dumps(parsed, indent=2))  # make sure it all went well

应该给您与上述相同的结果，但这次将不依赖于 } 在您的 JSON 对象“关闭”时作为新行的第一个字符。它也应该适用于背靠背堆叠的 JSON 数组。