开发grad_fn、next_functions两个API 并暴露到python端- 修改单侧文件路径到合理位置 (#55311)

* [尝试] 给tensor增加一个属性, 这个属性是一个定值 1

* 暴露gradnode 并构建gradnode新的方法(用来测试)进行暴露给python python端可以访问

* 开发grad_fn、next_functions两个API 并暴露到python端- 做一些规范化处理

* 增加一个单元测试

* 优化 code-style

* 将单侧文件迁到正确的位置

* 优化 code-style

* 删除无用注释

* 解决 __main__ has no attribute

* 修改单侧文件

* 修改单侧脚本-temp

python/paddle/fluid/tests/unittests/test_grad_fn_and_next_functions.py → test/legacy_test/test_grad_fn_and_next_functions.py

@@ -18,12 +18,12 @@ Test the tensor attribute grad_fn and the properties of the reverse node grad_no
 import unittest
 
 import paddle
-import paddle.nn as nn
+from paddle import nn
 
 
 class Testmodel(nn.Layer):
     def __init__(self):
-        super(Testmodel, self).__init__()
+        super().__init__()
 
     def forward(self, x):
         y = x**2
@@ -74,7 +74,7 @@ class TestAnonmousSurvey(unittest.TestCase):
     def test_grad_fn_and_next_funs(self):
         self.check_func(self.output.grad_fn, self.output_grad_fn["grad_fn"])
 
-    def check_func(self, grad_fn: grad_fn, grad_fn_json: dict) -> None:
+    def check_func(self, grad_fn, grad_fn_json) -> None:
         """
         Check each node, grad_fn is tensor attribute. grad_fn_json is structure of next_node.
 
@@ -82,14 +82,8 @@ class TestAnonmousSurvey(unittest.TestCase):
             grad_fn (grad_fn): grad_fn of node
             grad_fn_json (dict): grad_node_json of node
         """
-        # print(grad_fn.name())
-        # assert func name
         self.assertEqual(grad_fn.name(), grad_fn_json["func_name"])
-        # Recursively test other nodes
-        if hasattr(grad_fn, 'next_functions') and grad_fn.next_functions[0]:
-            next_funcs_json = grad_fn_json["next_funcs"]
-            for u in grad_fn.next_functions:
-                self.check_func(u, next_funcs_json[u.name()])
 
 
-unittest.main()
+if __name__ == "__main__":
+    unittest.main()