Additional refactoring

choices.py

@@ -0,0 +1,23 @@
+import models
+import db
+
+
+def season_choices():
+    """ Query the database for available seasons.
+    This returns a list of tuples with the season ID and a display string.
+    """
+    sql, args = db.load_season()
+    seasons = db.query_db(sql, args, cls=models.Season)
+    choices = [(s.id, f'{s.code}: {s.game}') for s in seasons]
+    choices.insert(0, (-1, 'No Season'))
+    return choices
+
+
+class SeasonChoicesIterable:
+    """
+    This is used to declare choices for WTForms SelectFields at class definition time.
+    Be aware that this uses an undocumented WTForms feature and is not guaranteed to work.
+    """
+    def __iter__(self):
+        for choice in season_choices():
+            yield choice