* [Add]Add Xdoctester

* [Fix]fix beta docstring

* [Doctest]change dirichlet docstring

* [Doctest]change gumbel docstring

* [Doctest]change bernoulli docstring

* [Doctest]change categorical docstring

* [Doctest]change ops.py docstring

* [Doctest]change conv docstring

* [Doctest]change distance docstring, test=docs_preview

* [Change]add ref

* [Change]patch xdoctest debug

* isort all files

* revert conflicting files

* revert conflicting files

* revert conflicting files

* [CodeStyle][py2][U008] remove unnecessary args in `super()`

* remove remained args

* revert changes in test_pylayer_op

* Revert "revert changes in test_pylayer_op"

This reverts commit ff185a9ae738afac3b0264f61bde6c6b7f72e7c4.

* revert some changes in example code

* update config

* re-blacken python code

* temporarily disable date and diff_py_file

* skip a format

* Fix W605 in tools folder by adding escape symbols

* Fix W605 in incubate and some other folders

* Fix W605 in /fluid/test folders

* Update tools/analysisPyXml.py
Co-authored-by: NNyakku Shigure <sigure.qaq@gmail.com>

* Add some changes to manual and auto escape symbols

* revert changes in transformer.py

* Fix new code with W605 error: add escape symbols

* revert changes in transformer.py

* revert changes in transformer.py
Co-authored-by: NNyakku Shigure <sigure.qaq@gmail.com>

* init gumbel api

* commit: update test file

* fix：bug

* update Gumbel API

* upgrade distribution/gumbel.py

* add tests/test_distribution_gumbel.py

* fix：code style

* fix：code style

* fix：code style

* fix：code style

* fix bug

* fix：code style

* fix：code style

* fix：rollback uniform

* fix：delete invalid code

* fix：bug and add static test

* fix：code style

* fix：code style

* fix：delete init transforms

* fix：bug

* fix：bug

* fix：code style

* fix：code style

* fix：add transforms

* fix：code style

* fix：code style

* fix：bug

* fix：bug

* fix：code style

* fix：code style

* fix：bug

* fix：code style

* fix：code style

* fix：bug for gumbel.py / add：judge transforms'len for transformed_distribution.py

* update gumbel.py

* fix：bug for test_distribution_gumbel.py

* fix：bug for test_distribution_gumbel_static.py

* fix：code style

* fix：code style

* fix：coverage

* fix：bug

* fix：bug

* fix：code style

* fix：bug

* delete：no use package for gumbel.py

* add：coverage transforms'len judge for test_distribution_gumbel.py

* fix：code style for test_distribution_gumbel.py

* fix：coverage

* fix：code style

* fix：code style

* fix：code style

* fix：code style

* fix：code style

* fix：en doc

* fix：param

* fix：copyright

* fixSample; test=document_fix
Co-authored-by: Ndasen <sen15530876201@163.com>