Bulk Upload not working for Polymodel in appengine datastore - google-app-engine

Question

Bulk upload for an Entity of type db.polymodel.PolyModel fails with the following error (I have managed to upload other Entities and all imports should be present):
[INFO ] Logging to bulkloader-log-20130901.191015
[INFO ] Throttling transfers:
[INFO ] Bandwidth: 250000 bytes/second
[INFO ] HTTP connections: 8/second
[INFO ] Entities inserted/fetched/modified: 20/second
[INFO ] Batch Size: 10
Traceback (most recent call last):
File "c:/program files (x86)/google/google_appengine/appcfg.py", line 171, in
<module>
run_file(__file__, globals())
File "c:/program files (x86)/google/google_appengine/appcfg.py", line 167, in
run_file
execfile(script_path, globals_)
File "c:\program files (x86)\google\google_appengine\google\appengine\tools\ap
pcfg.py", line 4252, in <module>
main(sys.argv)
File "c:\program files (x86)\google\google_appengine\google\appengine\tools\ap
pcfg.py", line 4243, in main
result = AppCfgApp(argv).Run()
File "c:\program files (x86)\google\google_appengine\google\appengine\tools\ap
pcfg.py", line 2402, in Run
self.action(self)
File "c:\program files (x86)\google\google_appengine\google\appengine\tools\ap
pcfg.py", line 3979, in __call__
return method()
File "c:\program files (x86)\google\google_appengine\google\appengine\tools\ap
pcfg.py", line 3791, in PerformUpload
run_fn(args)
File "c:\program files (x86)\google\google_appengine\google\appengine\tools\ap
pcfg.py", line 3682, in RunBulkloader
sys.exit(bulkloader.Run(arg_dict))
File "c:\program files (x86)\google\google_appengine\google\appengine\tools\bu
lkloader.py", line 4395, in Run
return _PerformBulkload(arg_dict)
File "c:\program files (x86)\google\google_appengine\google\appengine\tools\bu
lkloader.py", line 4206, in _PerformBulkload
LoadConfig(config_file)
File "c:\program files (x86)\google\google_appengine\google\appengine\tools\bu
lkloader.py", line 3873, in LoadConfig
Loader.RegisterLoader(cls())
File "SubscribLoader.py", line 23, in __init__
('description', lambda x: x.decode('utf-8')),
File "c:\program files (x86)\google\google_appengine\google\appengine\tools\bu
lkloader.py", line 2674, in __init__
GetImplementationClass(kind)
File "c:\program files (x86)\google\google_appengine\google\appengine\tools\bu
lkloader.py", line 968, in GetImplementationClass
implementation_class = db.class_for_kind(kind_or_class_key)
File "c:\program files (x86)\google\google_appengine\google\appengine\ext\db\_
_init__.py", line 296, in class_for_kind
raise KindError('No implementation for kind \'%s\'' % kind)
google.appengine.ext.db.KindError: No implementation for kind 'DbSubscrib
'
Here is the command Line :
appcfg.py upload_data --config_file=SubscribLoader.py --filename=Subscrib.csv --
kind=(DbProduct,DbSubscrib) --url=https://.../_ah/remote_api -A appname
Here is the Loader Class
import datetime
from google.appengine.tools import bulkloader
from Db.shop.DbSubscrib import DbSubscrib
class SubscribLoader (bulkloader.Loader):
def __init__(self):
bulkloader.Loader.__init__(self, ('DbProduct','DbSubscrib'),
[
('name', lambda x: x.decode('utf-8')),
('createDate',
lambda x: datetime.datetime.strptime(x, '%m/%d/%Y').date()),
('level', lambda x: x.decode('utf-8')),
('duration', lambda x: x.decode('utf-8')),
('service', lambda x: x.decode('utf-8')),
('description', lambda x: x.decode('utf-8')),
])
loaders = [SubscribLoader]
DbSubcrib derives from DbProduct which drives from polymodel.PolyModel
Btw, I have tried to add another extra property 'class' which is hardcoded to DbSubscrib' (also tried to add 2 properties 'DbProduct' and 'DbSubscrib', without any luck.
Any help is much appreciated. I could not find a document on goole's site that goes into any nuances around PolyModel and bulkupload.

Answer 1

Ok, your problem is you can't upload DbSubScrib, you need to us DbProduct. If you look at any DbSubScrib as it is stored in the Datastore it is a DbProduct class, and the subclass will have an class attribute in the datastore of storing the inheritance class names
e.g
class value: ["DbProduct", "DbSubScrib"]
Chnage your loader class to DbProduct and it will work.

Answer 2

After a little tinkering, found the issue in google appengine's bulkuploader : it seems there was an attempt to make bulkupload work for PolyModel but not sure why this part was not fixed (or tested). Perhaps I am missing something - in anycase it works for me with these changes... The fix is in the following line of google.appengine.tools.bulkloader.py :
class BulkTransporterApp(object):
"""Class to wrap bulk transport application functionality."""
def __init__(self,
....
....
line 3399 - old - self.kind = arg_dict['kind']
line 3399 - new - self.kind = ParseKind (arg_dict['kind'])
After this change I was able to upload.
I have fixed the Bulkuploader module and command line above for how it should be to upload a PolyModel.