* [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

* 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 benchmark and communicator config

* fix bugs of the_one_ps

* multi program and fix bug in optimizer

* multi program in the_one_ps

* public commcontext

* ps optimizer multi programs

* cvm & datanorm backend

* fix dim

* fix unittest

* fix

* the one ps merge

* remove comm

* add DownpourLiteWorker

* all

* fix

* fix

* device worker downpour lite

* fix

* fix bug in global shuffle

* save inference model

* fix & add log

* fix

* remove log

* fix

* fix save summary

* fix

* fix pscore

* fix

* fix

* fix

* fix

* fix

* remove logs

* fix

* fix

* fix

* fix

* fix

* add some comments

* fix
Co-authored-by: Nesythan <esythan@126.com>

Change-Id: I2e82dfcee6a1d0512b94cebc32281123fa5bf597

* pretty print for datafeed error

Change-Id: I056a8b6f03608e96679a83846c97aed289cef7e6

* fix fleet dist infer ut

* fix one ps gradient clip

* test=develop, add distributed_infer

* add tensor table

* fix ut

Change-Id: I151e152919a1863db07792bffb42d0ca68995756

* oneps (3/4)
Co-authored-by: NMrChengmo <cmchengmo@163.com>
Co-authored-by: Nmalin10 <malin10@baidu.com>
Co-authored-by: Nchengmo <chengmo@baidu.com>

* fix test_dist_fleet_heter_ctr & peformance update

* test=develop, bug fix

* test=develop, add ps auto

* add print test_dist UT elapsed time

* UT elapsed time optimize

* add save/load for parameter server

* support ps-gpu

* move paddle.fleet to paddle.distributed.fleet

* test=develop,test=document_fix, remove the out args

* fleet_util move to paddle.fleet
Co-authored-by: NWuHaobo <wuhaobo1994@gmail.com>
Co-authored-by: Ntangwei12 <tangwei12@baidu.com>

Integrated Trainer of Parameter Server (API add `fluid.contrib.layers.sparse_embedding` only) (#22957)

* Integrated Trainer of Parameter Server

This reverts commit 66fce9e8.

Fleet Parameter Server API Integrated

* add thread barrier for the compiled program

* add half_async in the communicator
* fix DistributedStrategy

* fix grad clip， clip op belongs to Backward op when running in Parameter Server mode.

* add distributed_strategy

add executor.FetchHandler for train/infer from the dataset

* refector geo sgd & communicator

* add print log for unittest of distributed training
test=develop

* fix save/load in Fleet
* add UT framework of Fleet