* [CodeStyle][py2][U004] unecessary explicit `object` inheritance in class definition

* fix an increment

* [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)`

* Fix F522: remove unused arguments

* add redirect_stderr argument in _run_cmd

* update config

* re-blacken python code

* temporarily disable date and diff_py_file

* skip a format

* [CodeStyle][F401] remove unused import in python/paddle/distributed

* remove pass

* empty commit

* Fix ValueError: list.remove(x): x not in list for meta_optimizer_names.

Fix ValueError: list.remove(x): x not in list for meta_optimizer_names.

* Fix split import.

Fix split import.

* add noqa after meta_optimizers in factory

* restort collective ops

* expand `import *`

* add noqa after required imports

* try to fix APIs without core.ops

* Revert "try to fix APIs without core.ops"

This reverts commit 6172beaf601e84bf61f2490c12c4739f0edaa5eb.

* fix an increment

* empty commit

* add noqa after required imports

* expand `import *`, fix ci error
Co-authored-by: NShuangchi He <34329208+Yulv-git@users.noreply.github.com>

* trim trailing whitespace

* fix `.cmake-format.py`

* revert npu ut changes, avoid npu ci error

* save load

* save load

* add unittest

* first commit

* second commit

* third commit

* remove SaveLocalFS in memory sparse table

* save dense param

* update

* push slot

* fix push show clk: int -> float

* add unittest

* fix sample

* unittest

* add AsExtra for op

* unittest

* modify fs.py

* modify fs.py

* fix some bugs

* add dataset hdfs config

* local change

* dataset use differenct hadoop ugi/fs_name

* add

* fix conflict

* fix

* remove logs

* code style

* fix

* code style

* code style

* fix

* code style

* save_dense_param

* fix

* fix

* fix

* fix

* change momentum in dense optimzer

* fix

* fix

* change fluid => paddle.static

* remove some unuseful code
Co-authored-by: Nesythan <esythan@126.com>

* 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

* add gpupsutil and afsclient; test=develop

* heterps:add fuse_allreduce op; test=develop
* add program_mode in minimize for pslib mode;test=develop

* fix hdfs and fleet_util for supporting save/load infer;test=develop

* topo and memory performance for heterps; test=develop
* add trainwithprofiler in heter trainier; test=develop

* test=develop, rm pathlib

* set default value to strategy in distributed_optimizer test=develop

* test=develop, bug fix

* test=develop, util documents

* move paddle.fleet to paddle.distributed.fleet

* fix merge3 test=develop

* 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>

* add hdfs ls retry time and sleep time, fix save inference
* test=develop

* fix cache table bug
* add save_paddle_inference_model
* fix hdfs util bug
* test=develop

* support change shuffle thread num
* support change train thread num
* fix receive shuffle data of each channel
* data norm stop gradient
* add check thread_tensor type and root_tensor type when merge metric
* remove sleep in shuffle, add config
* add config of pslib client to client communication
* fix xbox str
* add data norm op testcase
* add flush in trainer finalize

* support preload thread
* sleep before fleet wrapper exit for pslib core dump
* optimize hdfs log
* fix master+patch bug

* add fleet util (fleet/utils/fleet_util.py): functions for users' convenience
* add some interface in hdfs util : hdfs is_file、hdfs cat

do some odd jobs, test=develop

* fix logging unable. test=develop

* unset sys.stdout for stream handler. test=develop

* fix newly add basicConfig. test=develop

* fix import error. test=develop

* fix utils config, test=develop

* reweite tools in lookup table utils, test=develop

* merge develop, test=develop

* add copy in setup, test=develop

* update api spec, test=develop

* add doc, test=develop

* prettifying doc, test=develop

* Update API.spec

update api.spec, test=develop

* Update lookup_table_utils.py

test=develop

* Update lookup_table_utils.py

test=develop

* merge develop, test=develop

* merge develop, test=develop

* init fix, test=develop

* fix in downloads, test=develop

* fix in setup.in, test=develop