* add cost interface

* update inferface and add unittest

* update unittest

* update inferface

* [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>

* update comp cost and completion for gpt auto search

* add unittest

* update reshard cost and cost estimator

* add unittest

* add dropout cost

* fix import error

* fix reshard code style error

* improve unittest coverage

* update comp cost

* add dist default op cost

* add dist fill constant batch size like op cost

* add elewise op cost

* add fill_constant_batch_size_like op cost unittest

* add unittest and remove fill_constant_batch_size_like grad op cost

* add to cmakelist

* fix unittest bug

* update base cost

* update unittest of cost model

* add unittest

* 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

* refactor cost model