* [CodeStyle][py2] remove `six` package (part2)

* six.ensure_str

* remove unused `import six`

* remove six from BUILTIN_LIKELY_MODULES

* remove six in example code

* remove some decode

* try to fix example code

* fix MockEtcdClient get/get_prefix returns data type

* fix MockEtcdClient get_prefix returns data

* fix MockEtcdClient get returns data

* remove `six` in pypi and conda requirements

* fix MockEtcdClient add_watch_callback/add_watch_prefix_callback returns data type

* refine MockEtcdClient

* 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

* trim trailing whitespace

* fix `.cmake-format.py`

* revert npu ut changes, avoid npu ci error

* irfftn; test = docutment_fix

* fft; test=document_fix

* fft; test=document_fix

* fft; test=document_fix

* subdata; test=document_fix

* adaptive_avg_pool2d; test=document_fix

* adaptive_avg_pool3d; test = document_fix

* ftt; test=document_fix

* ftt; test=document_fix

* AvgPool1D; test=document_fix

* avg_pool1d; test=document_fix

* test=document_fix

* test=document_fix

* test=document_fix

* test=document_fix

* fft; test=document_fix

* emb; test=document_fix

* emb; test=document_fix

* emb;test=document_fix

* fold; test=document_fix

* fold; test=document_fix

* fold; test=document_fix

* fold;test=document_fix

* GELU;test=document_fix

* update irfftn docs;test=document_fix

* Update fft.py

* Update fft.py

* Update common.py

* Update common.py

* Update fft.py

* Update input.py

* Update pooling.py

* dropout2d; test=document_fix

* Fold; test=document_fix

* update fold math;test=document_fix

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

* add name attribute to code-block, test=document_fix

* remove redundant labels, test=document_fix

* remove redundant labels (from upstream), test=document_fix

* more COPY-FROM (try multiple code example), test=document_fix

* empty commit, try to trigger PR-CI-build

* fix some `Examples:` format issues

* fix some ci errors

* fix the bug that _DataLoaderIterMultiProcess use time to generate the seed

* use np.random.randint to generate a base seed

* fix structure infos conflict in static return_list mode. test=develop

* 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

* fix usage of prefetch_factor

* add assert

* add docstring and change prefetch_factor when num_workers=0

* fix doc

* optimize performance

* fix

* improve coverage

* fix

* fix

* eager math op, test=develop

* eager support lookahead, test=develop

* refine,test=develop

* refine doc, test=develop

* refine,test =develop

* refie, test=develop

* refie, test=develop

* refie, test=develop

* test_paddle_multiprocessing

* refine, test=develop

* refine, test=develop

* fix bug, test=develop

* refine, test=develop

* dataloader, test=develop

* refine, test=develop

* refine, test=develop

* refine, test=develop

* test_datasets timeout, test=develop

* refine, test=develop

* refactor eager flags

* fix flags error when we switch from eager to dygraph

* fix ci problem

* fix ci

* fix ci

* merge develop and fix code style

* merge develop and fix code style

* fix op test error

* fix op test error

* fix op test error

* fix op test error

* fix op test error

* merge develop

* add event record for model profiling

* fix format

* fix format

* fix code example bug

* no

* add profiler statistic

* add profiler feature

* fix bug

* fix bug

* fix bug

* fix bug

* required: gpu

* required: gpu

* fix bug

* required: gpu

* fix ci bug

* fix ci error

* fix ci error

* upgrade document

* fix doc

* fix ci bug

* add doc and fix bug

* nothing

* fix bug

* fix format bug

* modify format

* add deprecated description for old profiler

* fix bug

* fix bug

* fix

* add load_profiler_reuslt doc

* add load_profiler_reuslt doc

* add load_profiler_reuslt doc

* help fix old profiler sample code

* add api doc

* fix format

* fix api doc

* fix api doc format

* fix api doc format

* fix api doc c format

* fix api doc format

* merge legacy to fluid

* Remove legacy code

* Remove legacy code

* Remove DataType test

* Using Tensor directly instead of using EagerTensor

* support gradient_accumulation

* make test_imperative_lod_tensor_to_selected_rows longer

* make test_imperative_lod_tensor_to_selected_rows longer

* refine code

* Rename all EagerTensor to Tensor

* Rename some EagerTensor to Tensor

* rename EagerTensor to EagerVariable

* add more test

* merge develop and refine code

* Rearranged Eager AutoCodeGen directory structure

* Removed USE_OP in Eager AutoCodeGen

* Enabled generation for Operators without Grad/Inputs/Outputs

* Resolved operators without input

* Fixed merge conflicts

* Enabled Eager AutoCodeGen for 10+ more operators

* Refactored Eager AutoCodeGen with more organized helper objects

* Enabled Eager AutoCodeGen for operators with multiple OpBases

* Adjusted Eager AutoCodeGen to Enable Passing Output Tensor as Input Argument

* Handled Dispensable Inputs/Outputs in Eager AutoCodeGen

* Adjusted function generation/call between Python-C API & Dygraph API

* Synchronized auto-generated Python-C API with Dygraph Forward Functions

* support more eager tensor api

* fix merge compile error

* fix compile error and fit develop code

* support pure CPU

* fix some logic error in eager_mode

* support _varbase_creator in eager mode

* Added safe_initialized interface to EagerTensor for use in processing dispensable inputs

* for eager mode

* refine

* support multiple constructor for eager tensor

* add place related code

* polish code

* specific randint with dtype of int64

* Support pure cpu test

* eager logic

* refine test in pure cpu

* eager logic

* eager logic

* eager logic, test=develop

* skip core.eager when in inference, test=develop

* refine, test=develop

* refine, test=develop

* call RetainGrad after run forward kernel, test=develop

* refine, test=develop

* support dygraph util, meta, guard test

* eager test case

* support inference test

* refine test and fix initializer failed

* modify eagertensor patch method

* add eagertensor.clear_grandint, test=develop

* refine, test=develop

* refine, test=develop

* refine, test=develop

* support create varbase and fix retain grad error

* call monkey_patch_varbase in _test_eager_guard, test=develop

* fix windows error

* split clear_gradient to clear_gradient and zero_grads, test=develop

* refine, test=develop

* refine, test=develop

* support test_imperative_basic test in eager mode

* remove additional log in variable.h

* remove additional log in variable.h

* remove additional code create in merge

* eager

* fix some eager logic, test=develop

* refine, test=develop

* refine, test=develop

* refine, test=develop

* patch_tensor_method_func, test=develop

* refine, test=develop

* eager test case, test=develop

* refine, test=develop

* eager, test=develop

* eager, test=develop

* eager optimizer, test=develop

* eager optimizer, test=develop

* eager test_imperative_optimizer_v2, test=develop

* eager, test=develop

* refine, test=develop

* refine, test=develop

* eager, test=develop

* add resize in share buffer to, test=develop

* eager, test=develop

* fix _share_buffer_to, test=develop

* refine, test=develop

* refine, test=develop

* support eager for dataloader,test=develop
Co-authored-by: Njim19930609 <jim19930609@gmail.com>
Co-authored-by: NJiabinYang <360788950@qq.com>

* remove cached kernel context

* revert dataloader format change

* hot fix for dataloader thread error

* polish comment

* fix type in comment, test=document_fix

* fix DataLoader exit with SIGABRT/SIGSEGV. test=develop

* fix drop_last not work in IterableDataset. test=develop

* add persistent_workers. test=develop

* del py2 code2

* fix test timeout

This reverts commit b2afc8df.

* add warning log for DataLoader output format imcompatible upgrade. test=develop

* fix Undefined variables

* fix Undefined variables

* add random state generate in DataLoader worker. test=develop

* fix dataloader exit hang when join re-enter. test=develop

* fixed docs.

* Fixed docs. test=document_fix

code bak.

fixed docs. test=document_fix

* Revert to previous version of python/paddle/fluid/backward.py

* fixed bugs.

* test=document_fix. Fixed examples.

* fix dataloader exit error if user exit program when dataloader is still iterating. test=develop