refs #323, code style refactor

gino/loader.py

@@ -51,12 +51,26 @@ def __getattr__(self, item):
 _none = object()
 
 
+def _get_column(model, column_or_name) -> Column:
+    if isinstance(column_or_name, str):
+        return getattr(model, column_or_name)
+
+    if isinstance(column_or_name, Column):
+        if column_or_name in model:
+            return column_or_name
+        raise AttributeError('Column {} does not belong to model {}'.format(
+            column_or_name, model))
+
+    raise TypeError('Unknown column {} with type {}'.
+                    format(column_or_name, type(column_or_name)))
+
+
 class ModelLoader(Loader):
-    def __init__(self, model, *column_names, **extras):
+    def __init__(self, model, *columns, **extras):
         self.model = model
         self._distinct = None
-        if column_names:
-            self.columns = self._column_loader(model, column_names)
+        if columns:
+            self.columns = [_get_column(model, name) for name in columns]
         else:
             self.columns = model
         self.extras = dict((key, self.get(value))
@@ -121,30 +135,14 @@ def get_from(self):
                                   getattr(subloader, 'on_clause', None))
         return rv
 
-    def load(self, *column_names, **extras):
-        if column_names:
-            self.columns = self._column_loader(self.model, column_names)
+    def load(self, *columns, **extras):
+        if columns:
+            self.columns = [_get_column(self.model, name) for name in columns]
 
         self.extras.update((key, self.get(value))
                            for key, value in extras.items())
         return self
 
-    @classmethod
-    def _column_loader(cls, model, column_names):
-        def column_formatter(column_name):
-            if isinstance(column_name, str):
-                return getattr(model, column_name)
-            elif isinstance(column_name, Column):
-                if column_name not in model:
-                    raise AttributeError('Column {} does not belong '
-                                         'to this model'.format(column_name))
-                return column_name
-            else:
-                raise TypeError('Unknown column name {} type {}'.
-                                format(column_name, type(column_name)))
-
-        return [column_formatter(column_name) for column_name in column_names]
-
     def on(self, on_clause):
         self.on_clause = on_clause
         return self
@@ -163,8 +161,8 @@ def none_as_none(self, enabled=True):
 
 
 class AliasLoader(ModelLoader):
-    def __init__(self, alias, *column_names, **extras):
-        super().__init__(alias, *column_names, **extras)
+    def __init__(self, alias, *columns, **extras):
+        super().__init__(alias, *columns, **extras)
 
 
 class ColumnLoader(Loader):