“e9549cbb78b01a570ded56b54cd1f5a0e5f44f12”上不存在“python/paddle/fluid/tests/unittests/dist_test_utils.py”
* 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