Squashed 'dagflow/' changes from a94bd56c..a9118567

a9118567 feat: load_variables, enable loading the files
REVERT: a94bd56c feat: load_variables, enable loading the files

git-subtree-dir: dagflow
git-subtree-split: a9118567dbe64a3c09339a3bbb953cde16e0defe

dagflow/dagflow/tools/schema.py

@@ -29,7 +29,8 @@ def LoadFileWithExt(*, key: str=None,**kwargs: Callable):
 
 from yaml import load, Loader
 def LoadYaml(fname: str):
-    return load(fname, Loader)
+    with open(fname, 'read') as file:
+        return load(file, Loader)
 
 from dictwrapper.dictwrapper import DictWrapper
 class NestedSchema(object):