* remove flatten in nn.py under fluid

* fix test case

* fix test case

* fix codestyle

* fix codestyle

* fix code style

* remove extra test case

* remove test case

* clear fluid api: warpctc, nce, identity_loss

* fix test_layers.py __init__.py

* fix loss.py

* change __init__.py and api calling method

* fix nce

* fix nce

* fix fluid.data

* delete warpctc api document

* fix loss.py

* fix ctc_loss

* fix test_warpctc_op.py

* fix test_layers.py

* fix some bug

* fix conflict

* fix ci bug

* Empty Commit test=allcase

* fix ci bug

* move conv3d

* remove unused import

* remove expand and eye under fluid.layers

* delete expand API test case

* Remove API: scatter
	replace paddle.fluid.layers.scatter with paddle.scatter

* modify the call of scatter from old style to new style

remove mean_iou which is not used in paddle 2.0

* Remove API: label_smooth (replace with paddle.nn.functional.label_smooth)
	Replace the paddle.fluid.layers.label_smooth with the
paddle.nn.functional.label_smooth

* modify the call of label_smooth from old style to new style

remove dice_loss which is not used in paddle 2.0

* clear fluid apis: center_loss, bpr_loss, edit_distance, hsigmoid, sampled_softmax_with_cross_entropy, rank_loss, margin_rank_loss,  sigmoid_cross_entropy_with_logits, huber_loss

* fix python/paddle/fluid/layers/loss.py

* fix test_layers.py

* fix CI bug

* fix nn.py

* remove apis in fluid.ops

* fix test_activation_nn_grad

* fix circle import error

* fix ops

* fix cos

* fix divide not inplace

* remove lazy-import part

remove crop which is not used in Paddle 2.0

* remove range

* clean fluid elementwise_pow, remove API

* clean elem_pow doc

* clean elementwise_mod

* clean elementwise min, floordiv, mod

* clean fluid elementwise_min

* fix elementwise_min op testcase

* remove chunk_eval

* remove paddle.fluid.dygraph.nn.conv2D

* fix ut

* fix conv fp16 UT

* move fluid.layers.deformable_conv to static.nn

* modify example code

* fix doc

* Update common.py
Co-authored-by: NLigoml <39876205+Ligoml@users.noreply.github.com>

* [CodeStyle][py2][U008] remove unnecessary args in `super()`

* remove remained args

* revert changes in test_pylayer_op

* Revert "revert changes in test_pylayer_op"

This reverts commit ff185a9ae738afac3b0264f61bde6c6b7f72e7c4.

* revert some changes in example code

* [CodeStyle][E711] use `is`/`is not` for comparison with `None`

* `self.assertTrue($A is None)` -> `self.assertIsNone($A)`

* `self.assertTrue($A is not None)` -> `self.assertIsNotNone($A)`

* `self.assertFalse($A is None)` -> `self.assertIsNotNone($A)`

* `self.assertEqual($A, None)` -> `self.assertIsNone($A)`

* `self.assertNotEqual($A, None)` -> `self.assertIsNotNone($A)`

* 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