Errata

There seem to be some issues with this code sample. A 'cacheSet' method is referenced in the text but not in the code, the save() method does not update the cache as described, and I get an 'EntityExistsException' thrown from save() [on form submit] when I add the memcache functionality. (It would be great to get the code posted online, to be able to rule out code transcription errors when debugging).

So far great book, much better than google's online docs.

However, figure 5-10 and 5-11 seem like they are incorrect. They claim to show the results of a query that uses 'level < 10'. I think what they are showing is a query that uses 'level > 10'.

Bottom row of figure 5-14 says

e2 3.14

But I think it is supposed to be

e1 3.14

The first

multipart.addBodyPart(htmlPart)

should be

multipart.addBodyPart(textPart)

Thanks for the book, its a good one!

Near the top of page 288, this line:

"You provide the name of the file that defines the exporters using the --filename=... command-line argument"

...should instead read:

"You provide the name of the file that defines the exporters using the --config_file=... command-line argument"

Note from the Author or Editor:
Thanks! You are correct, this instance of "--filename" (first paragraph of page 288) should be "--config_file". (The --filename argument is for the data file.)

App Engine has heavily revised the bulk data loader tool since the 1st edition of this book was published. The Loader/Exporter interface has been deprecated in favor of a config-based declarative syntax for defining mappings. I recommend going to the official documentation on Google's website the latest information: http://code.google.com/appengine/docs/python/tools/uploadingdata.html