* Merge branch 'reduce_sum' of https://github.com/GhostScreaming/Paddle into mine_fluid_clean_common.

* Fix some bugs.

* Clean APIs in python/paddle/fluid/layers/control_flow.py

* Polish code style.

* Change API.

* Fix some bugs.

* Fix some bugs.

* clean elem_arithmetic part6 unittest

* delete op_name_conflict unittest

* restore test_op_name_conflict

* fix codestyle test_op_function_generator

* remove reshape in nn.py under fluid

* remove reshape reference

* fix test case

* fix test case in distribution.uniform

* remove fluid reshape reference

* update config

* re-blacken python code

* temporarily disable date and diff_py_file

* skip a format

* [CodeStyle] remove all future import

* revert test_error.py

* restore future import in example code

[CodeStyle][NPU] use np.testing.assert_allclose instead of self.assertTrue(np.allclose(...)) (part 1) (#44988)

* autofix

* try resolve precision issues

* revert some changes

* clean some `err_msg`

* 0.0001 -> 1e-4

* update commented assert code

* try to fix some shape errors

* `numpy` -> `np`

* empty commit, trigger kunlun ci, test=kunlun

* empty commit, retrigger kunlun ci, test=kunlun

* empty commit, trigger kunlun ci, try fix npu memcpy_h2d, test=kunlun

* try fix npu import error, test=kunlun

[CodeStyle] use np.testing.assert_array_equal instead of self.assertTrue(np.array_equal(...)) (#44947)

* automatically fix

* update comments

* numpy -> np

* self.assertEqual(..., True)

* wrong usage (err_msg=True)

这不是修复导致的错误，这些是原来 `self.assertTrue(..., True)`
的错误用法，因此在修复后将其认为位置参数 `err_msg`

* some missing fix

* change fluid.mean to paddle.mean

* reverse some old code examples

* use yapf to format all python file

* yapf exclude two unittests file for they rely on writing and reading file, and format will break them

* disable diff_py_file because too many diff files cause command following failed

test=develop

[while grad]Support pruning op in find_op_path about while sub-block when appending backward (#25330)

Prune OPs which are not related with loss in while sub-block when constructing backward OP path.

* Polish error Info in while_loop test=develop

* support to modify dict and list in while_loop test=develop

* polish code test=develop

1. Add basic support for `for in range` loop
2. Move `test_dygraph_to_static_*` to `dygraph_to_static` dir and rename them
3. Add test case for dict in while_loop

Modify english document and unittest of while_loop

This PR makes assign op support LoDTensorArray and enable the loop_vars in
while_loop to support tuple or list.

1. Make while_op accept GPU conditional data
2. Add more complex test cases for while_loop API

Add basic while_loop