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@mikegrima
Last active May 9, 2023 21:14
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Un-json nested JSON strings from AWS Config
import datetime
import json
from typing import Any
from urllib.parse import unquote_plus
def un_wrap_json(json_obj: Any) -> Any:
"""Helper function to unwrap nested JSON in the AWS Config resource configuration."""
# pylint: disable=C0103,W0703,R0911
# Is this a field that we can safely return?
if isinstance(json_obj, (type(None), int, bool, float)): # noqa
return json_obj
# Is this a Datetime? Convert it to a string and return it:
if isinstance(json_obj, datetime.datetime):
return str(json_obj)
# Is this a Dictionary?
if isinstance(json_obj, dict):
decoded = {}
for k, v in json_obj.items():
decoded[k] = un_wrap_json(v)
# Is this a List?
elif isinstance(json_obj, list):
decoded = []
for x in json_obj:
decoded.append(un_wrap_json(x))
# Yes, try to sort the contents of lists. This is because AWS does not consistently store list ordering for many resource types:
try:
sorted_list = sorted(decoded)
decoded = sorted_list
except Exception: # noqa # nosec # If we can't sort then NBD
pass
else:
# Try to load the JSON string:
try:
# Check if the string starts with a "[" or a "{" (because apparently '123' is a valid JSON 😒😒😒)
for check_field in {"{", "[", '"{', '"['}: # Some of the double-wrapping is really ridiculous 😒
if json_obj.startswith(check_field):
decoded = json.loads(json_obj)
# If we loaded this properly, then we need to pass the decoded JSON back in for all the nested stuff:
return un_wrap_json(decoded)
# Check if this string is URL Encoded - if it is, then re-run it through:
decoded = unquote_plus(json_obj)
if decoded != json_obj:
return un_wrap_json(decoded)
return json_obj
# If we didn't get a JSON back (exception), then just return the raw value back:
except Exception: # noqa
return json_obj
return decoded
result = un_wrap_json('{ "some": [{ "nested": "{\\"json\\": \\"string\\"}" }] }')
assert type(result) == dict
assert result == {"some": [{"nested": {"json": "string"}}]}
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