Remove the responsibility of setting a default language from multilang.

Caller now has to do it.  No need to avoid circular deps, no need to do
much of anything at all.

pokedex/db/__init__.py

@@ -1,7 +1,7 @@
-from sqlalchemy import MetaData, Table, engine_from_config, orm
+from sqlalchemy import engine_from_config, orm
 
 from ..defaults import get_default_db_uri
-from .tables import metadata
+from .tables import Language, metadata
 from .multilang import MultilangSession, MultilangScopedSession
 
 
@@ -41,7 +41,13 @@ def connect(uri=None, session_args={}, engine_args={}, engine_prefix=''):
 
     all_session_args = dict(autoflush=True, autocommit=False, bind=engine)
     all_session_args.update(session_args)
-    sm = orm.sessionmaker(class_=MultilangSession, **all_session_args)
+    sm = orm.sessionmaker(class_=MultilangSession, language_class=Language,
+        **all_session_args)
     session = MultilangScopedSession(sm)
 
+    # Default to English
+    session.default_language = session.query(Language) \
+        .filter_by(identifier=u'en') \
+        .one()
+
     return session

pokedex/db/multilang.py

@@ -154,26 +154,22 @@ def create_translation_table(_table_name, foreign_class, relation_name,
     return Translations
 
 class MultilangSession(Session):
-    """A tiny Session subclass that adds support for a default language."""
-    _default_language_id = 9  # English.  XXX magic constant
+    """A tiny Session subclass that adds support for a default language.
+
+    Caller will need to assign something to `default_language` before this will
+    actually work.
+    """
+    _default_language_id = 0  # Better fill this in, caller
 
     def __init__(self, *args, **kwargs):
-        try:
         self.language_class = kwargs.pop('language_class')
-        except KeyError:
-            # Set the default language_class
-            # We need to import here, to prevent a circular depencency
-            from pokedex.db.tables import Language
-            self.language_class = Language
         super(MultilangSession, self).__init__(*args, **kwargs)
 
     @property
     def default_language(self):
-        # Need to import tables here to avoid a circular dependency
-        from pokedex.db import tables
-        query = self.query(self.language_class)
-        query = query.filter_by(id=self._default_language_id)
-        return query.one()
+        return self.query(self.language_class) \
+            .filter_by(id=self._default_language_id) \
+            .one()
 
     @default_language.setter
     def default_language(self, new):