This reverts commit 5a6c974e.

* 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

* modify test_load_op save path from /tmp to ./, test=develop

* trigger kunlun ci, test=kunlun

* trigger kunlun ci, test=kunlun

* add load_op_xpu for Baidu Kunlun, test=kunlun

* add is_compiled_with_xpu for unit test, test=kunlun

* add is_compiled_with_xpu for unit test, test=kunlun

test=develop