Added test decorator to test for the availability of a database

bob/bio/base/test/utils.py

@@ -58,6 +58,20 @@ def grid_available(test):
       raise SkipTest("Skipping test since gridtk is not available: %s" % e)
   return wrapper
 
+def db_available(dbname):
+  '''Decorator that checks if a given bob.db database is available.
+  This is a double-indirect decorator, see http://thecodeship.com/patterns/guide-to-python-function-decorators'''
+  def wrapped_function(test):
+    @functools.wraps(test)
+    def wrapper(*args, **kwargs):
+      try:
+        __import__('bob.db.%s' % dbname)
+        return test(*args, **kwargs)
+      except ImportError as e:
+        raise SkipTest("Skipping test since the database bob.db.%s seems not to be available: %s" % (dbname,e))
+    return wrapper
+  return wrapped_function
+
 
 atnt_default_directory = os.environ['ATNT_DATABASE_DIRECTORY'] if 'ATNT_DATABASE_DIRECTORY' in os.environ else "/idiap/group/biometric/databases/orl/"
 global atnt_downloaded_directory