Google app engine backup dump to json

gae_to_json.py

import sys
import json
import datetime
sys.path.append('/usr/local/Caskroom/google-cloud-sdk/latest/google-cloud-sdk/platform/google_appengine/')
from google.appengine.api.files import records
from google.appengine.datastore import entity_pb
from google.appengine.api import datastore

def extract(index):
    raw = open('backups/2020-11-10T18:54:56_95621/default_namespace/all_kinds/output-'+str(index), 'r')
    reader = records.RecordsReader(raw)
    result = []

    for record in reader:
        entity_proto = entity_pb.EntityProto(contents=record)
        entity = datastore.Entity.FromPb(entity_proto)
        if entity.kind().startswith('foo_'):
            rec = dict(entity)
            # https://cloud.google.com/appengine/docs/standard/python/datastore/keyclass
            rec['id'] = entity.key().id_or_name()
            rec['kind'] = entity.kind()
            result.append(rec)

    return result

def extract_all():
    # put your number of output-* files
    return [entry for i in range(0, 23) for entry in extract(i)]

class DumpEncoder(json.JSONEncoder):
    def default(self, obj):
        if isinstance(obj, datetime.datetime):
            return obj.isoformat()
        return json.JSONEncoder.default(self, obj)

print json.dumps(extract_all(), cls=DumpEncoder)