如何在Python中将Amazon Ions格式化为有效的JSON？

Question

在Amazon QLDB Ledger数据库的python驱动程序的示例代码中，该函数可打印Amazon Ion对象：

def print_result(cursor):
"""
Pretty print the result set. Returns the number of documents in the result set.

:type cursor: :py:class:`pyqldb.cursor.stream_cursor.StreamCursor`/
              :py:class:`pyqldb.cursor.buffered_cursor.BufferedCursor`
:param cursor: An instance of the StreamCursor or BufferedCursor class.

:rtype: int
:return: Number of documents in the result set.
"""
result_counter = 0
for row in cursor:
    # Each row would be in Ion format.
    logger.info(dumps(row, binary=False, indent='  ',
                      omit_version_marker=True))
    result_counter += 1
return result_counter

对于我自己的应用程序，我需要将此Amazon Ion对象转换为JSON，以便将其返回到来自长生不老药应用程序的函数调用。

所以我尝试了以下代码：

def get_result(cursor):
"""
Pretty print the result set. Returns the number of documents in the result set.

:type cursor: :py:class:`pyqldb.cursor.stream_cursor.StreamCursor`/
              :py:class:`pyqldb.cursor.buffered_cursor.BufferedCursor`
:param cursor: An instance of the StreamCursor or BufferedCursor class.

:rtype: int
:return: Number of documents in the result set.
"""

result = []
for row in cursor:

    # Each row would be in Ion format.
    result.append(dumps(row, binary=False,
                        omit_version_marker=True))

return result

但是我没有获得有效的JSON对象。上面函数的结果是：

['{version:\\"BGBl. II Nr. 163/2007\\",valid:true,url:\\"https://www.ris.bka.gv.at/GeltendeFassung.wxe?Abfrage=Bundesnormen&Gesetzesnummer=20005279\\",subject:\\"Einweisungsbest\\\\xe4tigung\\",state:\\"in use\\",retrieved_on:null,name:\\"Medizinproduktebetreiberverordnung (MPBV)\\",id:null,country:\\"AT\\",confirmation_template:[]}"', '"{subject:\\"Einweisungsbest\\\\xe4tigung\\",name:\\"Medizinproduktebetreiberverordnung (MPBV)\\",country:\\"AT\\",url:\\"https://www.ris.bka.gv.at/GeltendeFassung.wxe?Abfrage=Bundesnormen&Gesetzesnummer=20005279\\",retrieved_on:2019-12-21T00:00:00.000000-00:00,version:\\"BGBl. II Nr. 163/2007\\",state:\\"in use\\",valid:true}']

[当我尝试通过json.dump之类转换Amazon Ion对象时

def get_result(cursor):
"""
Pretty print the result set. Returns the number of documents in the result set.

:type cursor: :py:class:`pyqldb.cursor.stream_cursor.StreamCursor`/
              :py:class:`pyqldb.cursor.buffered_cursor.BufferedCursor`
:param cursor: An instance of the StreamCursor or BufferedCursor class.

:rtype: int
:return: Number of documents in the result set.
"""

result = []
for row in cursor:

    # Each row would be in Ion format.
    result.append(json.dumps(dumps(row, binary=False,
                                   omit_version_marker=True)))

return result

我得到以下结果：

['"{version:\\"BGBl. II Nr. 163/2007\\",valid:true,url:\\"https://www.ris.bka.gv.at/GeltendeFassung.wxe?Abfrage=Bundesnormen&Gesetzesnummer=20005279\\",subject:\\"Einweisungsbest\\\\xe4tigung\\",state:\\"in use\\",retrieved_on:null,name:\\"Medizinproduktebetreiberverordnung (MPBV)\\",id:null,country:\\"AT\\",confirmation_template:[]}"', '"{subject:\\"Einweisungsbest\\\\xe4tigung\\",name:\\"Medizinproduktebetreiberverordnung (MPBV)\\",country:\\"AT\\",url:\\"https://www.ris.bka.gv.at/GeltendeFassung.wxe?Abfrage=Bundesnormen&Gesetzesnummer=20005279\\",retrieved_on:2019-12-21T00:00:00.000000-00:00,version:\\"BGBl. II Nr. 163/2007\\",state:\\"in use\\",valid:true}"']

在两种情况下我都没有获得有效的JSON对象。

在Amazon Ion Docs / Cookbook中Link to the Cookbook是如何将离子下转换为用Java代码编写的JSON的示例，但我无法在python或Amazon QLDB Ledger数据库的python驱动程序中重现该示例。

所以，如何在Python中将Amazon Ions格式化为有效的JSON？

Answer 1

您可以使用pyion2json作为将Ion转换为JSON的工具。它使用down-converting cookbook中列出的规则来执行转换。

import json
import amazon.ion.simpleion as ion
from pyion2json import ion_cursor_to_json

ion_str = '''[
    {
        version:"BGBl. II Nr. 163/2007",
        valid:true,
        url:"https://www.ris.bka.gv.at/GeltendeFassung.wxe?Abfrage=Bundesnormen&Gesetzesnummer=20005279",
        subject:"Einweisungsbest\xe4tigung",
        state:"in use",
        retrieved_on:null,
        name:"Medizinproduktebetreiberverordnung (MPBV)",
        id:null,
        country:"AT",
        confirmation_template:[]
    },
    {
        subject:"Einweisungsbest\xe4tigung",
        name:"Medizinproduktebetreiberverordnung (MPBV)",
        country:"AT",
        url:"https://www.ris.bka.gv.at/GeltendeFassung.wxe?Abfrage=Bundesnormen&Gesetzesnummer=20005279",
        retrieved_on:2019-12-21T00:00:00.000000-00:00,
        version:"BGBl. II Nr. 163/2007",
        state:"in use",
        valid:true
    }
]'''

print(
    json.dumps(
        ion_cursor_to_json(
            ion.loads(ion_str)
        ),
        indent=' '
    )
)

将给予：
[
 {
  "version": "BGBl. II Nr. 163/2007",
  "valid": true,
  "url": "https://www.ris.bka.gv.at/GeltendeFassung.wxe?Abfrage=Bundesnormen&Gesetzesnummer=20005279",
  "subject": "Einweisungsbest\u00e4tigung",
  "state": "in use",
  "retrieved_on": null,
  "name": "Medizinproduktebetreiberverordnung (MPBV)",
  "id": null,
  "country": "AT",
  "confirmation_template": []
 }
]