initial work for django plugin

mypy_django_plugin/helpers.py

@@ -0,0 +1,19 @@
+from mypy.checker import TypeChecker
+from mypy.nodes import SymbolTableNode, Var
+
+
+def is_class_variable(symbol_table_node: SymbolTableNode) -> bool:
+    # MDEF: class member definition
+    is_class_variable = symbol_table_node.kind == 2 and type(symbol_table_node.node) == Var
+    if not is_class_variable:
+        return False
+
+    return True
+
+
+def lookup_django_model(mypy_api: TypeChecker, fullname: str) -> SymbolTableNode:
+    module, _, model_name = fullname.rpartition('.')
+    try:
+        return mypy_api.modules[module].names[model_name]
+    except KeyError:
+        return mypy_api.modules['django.db.models'].names['Model']