GitLab

* Upgrade the version of isort

* sort the order of importing modules

* [Feature] Choose storage backend by the prefix of filepath

* refactor FileClient and add unittest

* support loading from different backends

* polish docstring

* fix unittet

* rename attribute str_like_obj to is_str_like_obj

* add infer_client method

* add check_exist method

* rename var client to file_client

* polish docstring

* add join_paths method

* remove join_paths and add _format_path

* enhance unittest

* refactor unittest

* singleton pattern

* fix test_clientio.py

* deprecate CephBackend

* enhance docstring

* refactor unittest for petrel

* refactor unittest for disk backend

* update io.md

* add concat_paths method

* improve docstring

* improve docstring

* add isdir and copyfile for file backend

* delete copyfile and add get_local_path

* remove isdir method of petrel

* fix typo

* add comment and polish docstring

* polish docstring

* rename _path_mapping to _map_path

* polish docstring and fix typo

* refactor get_local_path

* add list_dir_or_file for FileClient

* add list_dir_or_file for PetrelBackend

* fix windows ci

* Add return docstring

* polish docstring

* fix typo

* fix typo

* deprecate the conversion from Path to str

* add docs for loading checkpoints with FileClient

* refactor map_path

* add _ensure_methods to ensure methods have been implemented

* fix list_dir_or_file

* rename _ensure_method_implemented to has_method

* assert both dep and new args exist at same time

* add unintest

* Update tests/test_utils/test_misc.py
Co-authored-by: Zaida Zhou <58739961+zhouzaida@users.noreply.github.com>

* Update tests/test_utils/test_misc.py
Co-authored-by: Zaida Zhou <58739961+zhouzaida@users.noreply.github.com>

* polish warning

* polish warning
Co-authored-by: Zaida Zhou <58739961+zhouzaida@users.noreply.github.com>

* [Docs] Add header for files

* change to OpenMMLab

* add headers for .cpp, .cu, .h, .cuh

* replace Open-MMLab with OpenMMLab

* support print using hooks before running.

* Support to print hook trigger stages.

* Print stage-wise hook infos. And make `stages` as class attribute of
`Hook`

* Add util function `is_method_overriden` and use it in
`Hook.get_trigger_stages`.

* Add unit tests.

* Move `is_method_overriden` to `mmcv/utils/misc.py`

* Improve hook info text.

* Add base_class argument type assertion, and fix some typos.

* Remove `get_trigger_stages` to `get_triggered_stages`

* Use f-string.

* add to_ntuple

* add unit test

* move unit tests to specific folders

* fix path error

* remove some assertions

* fix ignore path

* Custom imports

* Resolve comments

* Add unittest

* Add unittest

* Rename custom_imports to import_modules_from_strings

* Move import_modules_from_strings ito misc.py and allow failed imports

* small change

* small change

* change mmcv.runner to os.path

* remove supports for python 2.7

* fix the unit test for python 3.5

* add python 3.8 in CI

* try ubuntu 18.04 as the environment

* add copyright header

* change # to // for cpp files

* add yapf and isort to travis

* minor formatting

* remove blank lines

* skip unit tests for progressbar when python2

* update travis to ubuntu 16.04

* use a newer version ffmpeg

* add -y to add-apt-repository