* replace PiecewiseDecay(LearningRateDecay) with PiecewiseDecay(LRScheduler)

* fix bug

* fix bug

* replace the StepDecay,MultiStepDecay,LambdaDecay with 2.0 version

* remove the CosineDecay in fluid

* Update test_basic_api_transformation.py

* remove the NaturalExpDecay in fluid

* fix bug

* remove the ExponentialDecay in fluid

* remove the InverseTimeDecay in fluid

* remove the InverseTimeDecay class

* fix bug

* add up34

* modify var name in loop

* revert changes in test_slice

* Revert "modify var name in loop"

This reverts commit 6d748e371afb417054ed0c6b36fd11e87959a90d.

* temporarily ignore test_slice.py

* add comment

* empty commit, re-trigger all ci

* fix inc

---------
Co-authored-by: NSigureMo <sigure.qaq@gmail.com>

remove fluid.initializer.UniformInitializer, ConstantInitializer, NormalInitializer, TruncatedNormalInitializer, XavierInitializer, BilinearInitializer, MSRAInitializer, NumpyArrayInitializer and calculate_gain.. (#49498)

* move UniformInitializer and ConstantInitializer

* more modify

* circular import resolved

* another circular import resolved?

* more circular import 2

* circular import 3

* change import paddle in metric.py

* BuildStrategy import from fluid

* modify the framework import path in common.py

* change rnn.py import, from static to original framework

* change import static in the nn folder

* default_main_program should import from common_ops_import

* add import paddle in param_attr.py

* use core not paddle module for using VarDesc

* another old uniform

* mistake that use Uniform instead of UniformInitializer

* modify UniformInitializer doc

* move fluid.NormalInitializer to nn.initializer.NormalInitializer

* remove import of Normal in fluid.layers.nn.py

* remove more import of old Normal

* remove more import of old Normal

* sample code modify and tests modify import

* is_listen_failed passing arg should be log file

* problem solved

* a mistake solved

* comments resoleved and remove paddle.fluid.initializer.TruncatedNormalInitializer

* remove paddle.fluid.initializer.XavierInitializer and paddle.fluid.initializer.MSRAInitializer

* remove paddle.fluid.initializer.BilinearInitializer NumpyArrayInitializer and set_global_initializer

* change fluid to static

* change static to fluid to avoid circular import in distributed_strategy.py

* fix example code and test_initializer

* ValueType

* sample code fix

* change set_global_initializer back to fluid

* put paddle.static.BuildStrategy.ReduceStrategy into the fuction to avoid circular import

* remove calculate_gain, delete BilinearInitializer and revert set_global_initializer

* change the time of using UniformInitializer, ConstantInitializer, NormalInitializer, TruncatedNormalInitializer, XavierInitializer, MSRAInitializer, NumpyArrayInitializer as few as possible

* fix argument incampatible

* fix more arg incompatible

* fix test_prelu_op_xpu.py Constant

* fix inaccurate doc

* more doc fix: default value

* [remove fluid] PRelu BilinearTensorProduct

* [remove fluid] PRelu BilinearTensorProduct Conv2DTranspose SequenceConv RowConv

* [remove fluid] PRelu BilinearTensorProduct Conv2DTranspose SequenceConv RowConv

* [remove fluid] PRelu BilinearTensorProduct Conv2DTranspose SequenceConv RowConv

* [remove fluid] PRelu BilinearTensorProduct Conv2DTranspose SequenceConv RowConv

* [remove fluid] PRelu BilinearTensorProduct Conv2DTranspose SequenceConv RowConv

* [remove fluid] PRelu BilinearTensorProduct Conv2DTranspose SequenceConv RowConv

* [remove fluid] PRelu BilinearTensorProduct Conv2DTranspose SequenceConv RowConv

* [Fluid Clean]Migrate utils files and delete dygraph_to_static dir

* fix setup.py.in

* fix import

* fix unittest

* fix code style

* fix unittest

* [remove fluid] under unittesets

* [remove fluid] under unittesets

* [remove fluid] under unittesets

* [remove fluid] under unittesets

* [remove fluid] under unittesets

* [remove fluid] under unittesets

* [remove fluid] under unittesets

* [remove fluid] under unittesets

* [remove fluid] under unittesets

* [remove fluid] under unittesets

* [remove fluid] under unittesets

* [remove fluid] under unittesets

* [remove fluid] under unittesets

* [remove fluid] under unittesets

* [remove fluid] under unittesets

* [remove fluid] under unittesets

* [Fluid Clean] Migrate program_translate.py/jit.py into paddle.jit dir

* remove paddle.fluid.dygraph.nn.conv2D

* fix ut

* fix conv fp16 UT

* 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

* 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

* integrated gast library

* integrated gast library

* fix unittest and remove ast2.py

* remove 'gast' from __all__ in __init__.py

* add copyright in other files

* fix copyright

Dy2stat failed when user writes return paddle.to_tensor(xxx), the reason is that visit_Expr doesn't work when the Expr is in return. Some other statements may trigger same bug. To fix it, we re-wrote a transformer to transform paddle.to_tensor to paddle.assign for all Call nodes.

paddle.to_tensor will be translated to paddle.assign in Dy2stat, however paddle.assign doesn't support int, float, bool. This PR added the supports.

This PR does exact the thing as the title. The reason is that we plan to develop 4 decorators

"dygraph_to_static_code"
"dygraph_to_static_program"
"dygraph_to_static_func"
"dygraph_to_static_output"

 The 4 decorators will emphasize different part when translating dygraph to static graph. Decorator name "dygraph_to_static_graph" is too big for the function it implements.

As the title

+ Refine code structure and move code related with control flow `if` into `ifelse_transformer.py`
+ Merge code of `ast_utils.py`  into `utils.py` 

* change dygraph_to_static_output to dygraph_to_static_graph. test=develop

* Remove duplicate code. test=develop

* Follow comments from Liujie. test=develop

* change dygraph_to_static_output to dygraph_to_static_graph. test=develop

* support dygraph to static graph for simple case.

* add test for dygraph API recognition. test=develop

* support basic to_variable api. test=develop

* update dict: dygraph_class_to_static_api

* add all tests of dygraph api. test=develop

* use gast/astor instead of ast/codegen for the compatibility of PY2 and PY3. test=develop

* add arg 'num_flatten_dims' for fc ast node. test=develop

* Modify names of class by Camel-Case.