I just tried to add two entity counts to my app's statistics page. Then I found out, the statistics API—released on 10/13/2009, version 1.2.6—is not available for development server.

You can run the following code without errors:
from google.appengine.ext.db import stats
global_stat = stats.GlobalStat.all().get()

But global_stat is always None.

So I ended up with a code as follows:
db_blog_count = memcache.get('db_blog_count')
if db_blog_count is None:
  blog_stat = stats.KindStat.all().filter('kind_name =', 'Blog').get()
  if blog_stat is None:
    db_blog_count = 'Unavailable'
  else:
    db_blog_count = blog_stat.count
  memcache.set('db_blog_count', db_blog_count, 3600)

The documentation didn't explicit mention whether if the statistics is available for development server or not—maybe I didn't read carefully, neither did Release Notes.

PS. I know the code is awful, str / int types mixed, terrible. But I am lazy to add and if clause in template file to check if db_blog_count is None or something like -1, or anything represents the data is not available.

PS2. The code should be just if blog_stat: (fourth line) and swap the next two statements if you know what I meant.