Remove supports for python 2.7 and bump version to 0.4.0 (#211)

* 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

.travis.yml

-dist: xenial
+dist: bionic
 sudo: required
 language: python
 
 before_install:
-  - sudo add-apt-repository -y ppa:mc3man/xerus-media
   - sudo apt-get update
-  - sudo apt-get install -y ffmpeg libjpeg-turbo*
+  - sudo apt-get install -y ffmpeg libturbojpeg
   - pip install -U git+git://github.com/lilohuang/PyTurboJPEG.git
 
 install:
   - pip install torch==1.4.0+cpu torchvision==0.5.0+cpu -f https://download.pytorch.org/whl/torch_stable.html
-  - rm -rf .eggs && pip install -e . codecov flake8 yapf isort mock
+  - rm -rf .eggs && pip install -e .
 
 cache:
   pip: true
@@ -23,8 +22,10 @@ python:
   - "3.5"
   - "3.6"
   - "3.7"
+  - "3.8"
 
 before_script:
+  - pip install codecov flake8 yapf isort
   - flake8
   - isort -rc --diff mmcv/ tests/ examples/
   - yapf -r -d mmcv/ tests/ examples/
@@ -41,7 +42,7 @@ deploy:
   on:
     branch: master
     tags: true
-    python: "3.6"
+    python: "3.7"
     distributions: sdist bdist_wheel
     skip_cleanup: true
     skip_upload_docs: true

README.rst

@@ -30,7 +30,7 @@ It provides the following functionalities.
 
 See the `documentation <http://mmcv.readthedocs.io/en/latest>`_ for more features and usage.
 
-Note: MMCV currently supports both Python 2.7 and 3.5+, but we plan to remove the support for Python 2. Please migrate to Python 3 as soon as possible.
+Note: MMCV requires Python 3.5+.
 
 
 Installation

docs/io.md

@@ -55,7 +55,7 @@ class TxtHandler1(mmcv.BaseFileHandler):
 Here is an example of `PickleHandler`.
 
 ```python
-from six.moves import cPickle as pickle
+import pickle
 
 class PickleHandler(mmcv.BaseFileHandler):
 

mmcv/fileio/handlers/base.py

@@ -2,9 +2,7 @@
 from abc import ABCMeta, abstractmethod
 
 
-class BaseFileHandler(object):
-
-    __metaclass__ = ABCMeta  # python 2 compatibility
+class BaseFileHandler(metaclass=ABCMeta):
 
     @abstractmethod
     def load_from_fileobj(self, file, **kwargs):

mmcv/fileio/handlers/pickle_handler.py

 # Copyright (c) Open-MMLab. All rights reserved.
-from six.moves import cPickle as pickle
+import pickle
 
 from .base import BaseFileHandler
 

mmcv/utils/__init__.py

@@ -5,8 +5,8 @@ from .misc import (check_prerequisites, concat_list, is_list_of, is_seq_of,
                    is_str, is_tuple_of, iter_cast, list_cast,
                    requires_executable, requires_package, slice_list,
                    tuple_cast)
-from .path import (FileNotFoundError, check_file_exist, fopen, is_filepath,
-                   mkdir_or_exist, scandir, symlink)
+from .path import (check_file_exist, fopen, is_filepath, mkdir_or_exist,
+                   scandir, symlink)
 from .progressbar import (ProgressBar, track_iter_progress,
                           track_parallel_progress, track_progress)
 from .registry import Registry, build_from_cfg
@@ -17,7 +17,7 @@ __all__ = [
     'list_cast', 'tuple_cast', 'is_seq_of', 'is_list_of', 'is_tuple_of',
     'slice_list', 'concat_list', 'check_prerequisites', 'requires_package',
     'requires_executable', 'is_filepath', 'fopen', 'check_file_exist',
-    'mkdir_or_exist', 'symlink', 'scandir', 'FileNotFoundError', 'ProgressBar',
-    'track_progress', 'track_iter_progress', 'track_parallel_progress',
-    'Registry', 'build_from_cfg', 'Timer', 'TimerError', 'check_time'
+    'mkdir_or_exist', 'symlink', 'scandir', 'ProgressBar', 'track_progress',
+    'track_iter_progress', 'track_parallel_progress', 'Registry',
+    'build_from_cfg', 'Timer', 'TimerError', 'check_time'
 ]

mmcv/utils/config.py

@@ -5,11 +5,11 @@ import shutil
 import sys
 import tempfile
 from argparse import ArgumentParser
+from collections import abc
 from importlib import import_module
 
 from addict import Dict
 
-from .misc import collections_abc
 from .path import check_file_exist
 
 BASE_KEY = '_base_'
@@ -46,7 +46,7 @@ def add_args(parser, cfg, prefix=''):
             parser.add_argument('--' + prefix + k, action='store_true')
         elif isinstance(v, dict):
             add_args(parser, v, prefix + k + '.')
-        elif isinstance(v, collections_abc.Iterable):
+        elif isinstance(v, abc.Iterable):
             parser.add_argument('--' + prefix + k, type=type(v[0]), nargs='+')
         else:
             print('cannot parse key {} of type {}'.format(prefix + k, type(v)))

mmcv/utils/misc.py

 # Copyright (c) Open-MMLab. All rights reserved.
-import collections
 import functools
 import itertools
 import subprocess
+from collections import abc
 from importlib import import_module
 
-import six
-
-# ABCs from collections will be deprecated in python 3.8+,
-# while collections.abc is not available in python 2.7
-try:
-    import collections.abc as collections_abc
-except ImportError:
-    import collections as collections_abc
-
 
 def is_str(x):
-    """Whether the input is an string instance."""
-    return isinstance(x, six.string_types)
+    """Whether the input is an string instance.
+
+    Note: This method is deprecated since python 2 is no longer supported.
+    """
+    return isinstance(x, str)
 
 
 def iter_cast(inputs, dst_type, return_type=None):
@@ -32,12 +26,12 @@ def iter_cast(inputs, dst_type, return_type=None):
     Returns:
         iterator or specified type: The converted object.
     """
-    if not isinstance(inputs, collections_abc.Iterable):
+    if not isinstance(inputs, abc.Iterable):
         raise TypeError('inputs must be an iterable object')
     if not isinstance(dst_type, type):
         raise TypeError('"dst_type" must be a valid type')
 
-    out_iterable = six.moves.map(dst_type, inputs)
+    out_iterable = map(dst_type, inputs)
 
     if return_type is None:
         return out_iterable
@@ -73,7 +67,7 @@ def is_seq_of(seq, expected_type, seq_type=None):
         bool: Whether the sequence is valid.
     """
     if seq_type is None:
-        exp_seq_type = collections_abc.Sequence
+        exp_seq_type = abc.Sequence
     else:
         assert isinstance(seq_type, type)
         exp_seq_type = seq_type

mmcv/utils/path.py

 # Copyright (c) Open-MMLab. All rights reserved.
 import os
 import os.path as osp
-import sys
 from pathlib import Path
 
-import six
-
 from .misc import is_str
 
-if sys.version_info <= (3, 3):
-    FileNotFoundError = IOError
-else:
-    FileNotFoundError = FileNotFoundError
-
 
 def is_filepath(x):
     if is_str(x) or isinstance(x, Path):
@@ -37,11 +29,7 @@ def mkdir_or_exist(dir_name, mode=0o777):
     if dir_name == '':
         return
     dir_name = osp.expanduser(dir_name)
-    if six.PY3:
-        os.makedirs(dir_name, mode=mode, exist_ok=True)
-    else:
-        if not osp.isdir(dir_name):
-            os.makedirs(dir_name, mode=mode)
+    os.makedirs(dir_name, mode=mode, exist_ok=True)
 
 
 def symlink(src, dst, overwrite=True, **kwargs):
@@ -50,7 +38,9 @@ def symlink(src, dst, overwrite=True, **kwargs):
     os.symlink(src, dst, **kwargs)
 
 
-def _scandir_py35(dir_path, suffix=None):
+def scandir(dir_path, suffix=None):
+    if (suffix is not None) and not isinstance(suffix, (str, tuple)):
+        raise TypeError('"suffix" must be a string or tuple of strings')
     for entry in os.scandir(dir_path):
         if not entry.is_file():
             continue
@@ -61,25 +51,6 @@ def _scandir_py35(dir_path, suffix=None):
             yield filename
 
 
-def _scandir_py(dir_path, suffix=None):
-    for filename in os.listdir(dir_path):
-        if not osp.isfile(osp.join(dir_path, filename)):
-            continue
-        if suffix is None:
-            yield filename
-        elif filename.endswith(suffix):
-            yield filename
-
-
-def scandir(dir_path, suffix=None):
-    if suffix is not None and not isinstance(suffix, (str, tuple)):
-        raise TypeError('"suffix" must be a string or tuple of strings')
-    if sys.version_info >= (3, 5):
-        return _scandir_py35(dir_path, suffix)
-    else:
-        return _scandir_py(dir_path, suffix)
-
-
 def find_vcs_root(path, markers=('.git', )):
     """Finds the root directory (including itself) of specified markers.
 

mmcv/utils/progressbar.py

 # Copyright (c) Open-MMLab. All rights reserved.
 import sys
+from collections.abc import Iterable
 from multiprocessing import Pool
+from shutil import get_terminal_size
 
-from .misc import collections_abc
 from .timer import Timer
 
 
@@ -19,10 +20,6 @@ class ProgressBar(object):
 
     @property
     def terminal_width(self):
-        if sys.version_info > (3, 3):
-            from shutil import get_terminal_size
-        else:
-            from backports.shutil_get_terminal_size import get_terminal_size
         width, _ = get_terminal_size()
         return width
 
@@ -79,11 +76,11 @@ def track_progress(func, tasks, bar_width=50, file=sys.stdout, **kwargs):
     """
     if isinstance(tasks, tuple):
         assert len(tasks) == 2
-        assert isinstance(tasks[0], collections_abc.Iterable)
+        assert isinstance(tasks[0], Iterable)
         assert isinstance(tasks[1], int)
         task_num = tasks[1]
         tasks = tasks[0]
-    elif isinstance(tasks, collections_abc.Iterable):
+    elif isinstance(tasks, Iterable):
         task_num = len(tasks)
     else:
         raise TypeError(
@@ -145,11 +142,11 @@ def track_parallel_progress(func,
     """
     if isinstance(tasks, tuple):
         assert len(tasks) == 2
-        assert isinstance(tasks[0], collections_abc.Iterable)
+        assert isinstance(tasks[0], Iterable)
         assert isinstance(tasks[1], int)
         task_num = tasks[1]
         tasks = tasks[0]
-    elif isinstance(tasks, collections_abc.Iterable):
+    elif isinstance(tasks, Iterable):
         task_num = len(tasks)
     else:
         raise TypeError(
@@ -193,11 +190,11 @@ def track_iter_progress(tasks, bar_width=50, file=sys.stdout, **kwargs):
     """
     if isinstance(tasks, tuple):
         assert len(tasks) == 2
-        assert isinstance(tasks[0], collections_abc.Iterable)
+        assert isinstance(tasks[0], Iterable)
         assert isinstance(tasks[1], int)
         task_num = tasks[1]
         tasks = tasks[0]
-    elif isinstance(tasks, collections_abc.Iterable):
+    elif isinstance(tasks, Iterable):
         task_num = len(tasks)
     else:
         raise TypeError(

mmcv/version.py

 # Copyright (c) Open-MMLab. All rights reserved.
-__version__ = '0.3.2'
+__version__ = '0.4.0'

requirements.txt

 addict
 numpy
 pyyaml
-six

setup.cfg

@@ -17,6 +17,6 @@ line_length = 79
 multi_line_output = 0
 known_standard_library = pkg_resources,setuptools
 known_first_party = mmcv
-known_third_party = Cython,addict,cv2,mock,numpy,pytest,resnet_cifar,six,torch,torchvision,yaml
+known_third_party = Cython,addict,cv2,numpy,pytest,resnet_cifar,torch,torchvision,yaml
 no_lines_before = STDLIB,LOCALFOLDER
 default_section = THIRDPARTY

setup.py

 import platform
 import re
-import sys
-from io import open  # for Python 2 (identical to builtin in Python 3)
 from pkg_resources import DistributionNotFound, get_distribution
 from setuptools import Extension, dist, find_packages, setup
 
@@ -24,11 +22,7 @@ def choose_requirement(primary, secondary):
     return str(primary)
 
 
-install_requires = ['addict', 'numpy', 'pyyaml', 'six']
-
-if sys.version_info < (3, ):
-    install_requires.extend(
-        ['backports.shutil_get_terminal_size', 'enum34', 'pathlib'])
+install_requires = ['addict', 'numpy', 'pyyaml']
 
 # If first not installed install second package
 CHOOSE_INSTALL_REQUIRES = [('opencv-python-headless>=3', 'opencv-python>=3')]
@@ -82,12 +76,11 @@ setup(
         'Development Status :: 4 - Beta',
         'License :: OSI Approved :: Apache Software License',
         'Operating System :: OS Independent',
-        'Programming Language :: Python :: 2',
-        'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3',
         'Programming Language :: Python :: 3.5',
         'Programming Language :: Python :: 3.6',
         'Programming Language :: Python :: 3.7',
+        'Programming Language :: Python :: 3.8',
         'Topic :: Utilities',
     ],
     url='https://github.com/open-mmlab/mmcv',

tests/test_config.py

 # Copyright (c) Open-MMLab. All rights reserved.
 import json
 import os.path as osp
+import sys
 
 import pytest
 
-from mmcv import Config, FileNotFoundError
+from mmcv import Config
 
 
 def test_construct():
@@ -25,7 +26,11 @@ def test_construct():
         assert isinstance(cfg, Config)
         assert cfg.filename == cfg_file
         assert cfg.text == open(cfg_file, 'r').read()
-        assert cfg.dump() == format_text
+        if sys.version_info >= (3, 6):
+            assert cfg.dump() == format_text
+        else:
+            loaded = json.loads(cfg.dump())
+            assert set(loaded.keys()) == set(cfg_dict)
 
 
 def test_fromfile():

tests/test_hooks.py

 import os.path as osp
 import sys
 import warnings
-
-from mock import MagicMock
+from unittest.mock import MagicMock
 
 import mmcv.runner
 

tests/test_misc.py

@@ -52,7 +52,7 @@ def test_requires_package(capsys):
     def func_b():
         pass
 
-    @mmcv.requires_package('six')
+    @mmcv.requires_package('numpy')
     def func_c():
         return 1
 

tests/test_path.py

 # Copyright (c) Open-MMLab. All rights reserved.
 import os.path as osp
-import sys
 from pathlib import Path
 
 import pytest
@@ -22,12 +21,8 @@ def test_fopen():
 
 def test_check_file_exist():
     mmcv.check_file_exist(__file__)
-    if sys.version_info > (3, 3):
-        with pytest.raises(FileNotFoundError):  # noqa
-            mmcv.check_file_exist('no_such_file.txt')
-    else:
-        with pytest.raises(IOError):
-            mmcv.check_file_exist('no_such_file.txt')
+    with pytest.raises(FileNotFoundError):
+        mmcv.check_file_exist('no_such_file.txt')
 
 
 def test_scandir():
@@ -43,4 +38,4 @@ def test_scandir():
     ])
     assert set(mmcv.scandir(folder, '.png')) == set()
     with pytest.raises(TypeError):
-        mmcv.scandir(folder, 111)
+        list(mmcv.scandir(folder, 111))

tests/test_progressbar.py

 # Copyright (c) Open-MMLab. All rights reserved.
 import os
-import sys
 import time
 
 try:
@@ -13,8 +12,6 @@ try:
 except ImportError:
     from io import StringIO
 
-import pytest  # isort:skip
-
 import mmcv  # isort:skip
 
 
@@ -23,10 +20,6 @@ def reset_string_io(io):
     io.seek(0)
 
 
-if sys.version_info[0] == 2:
-    pytest.skip('skipping tests for python 2', allow_module_level=True)
-
-
 class TestProgressBar(object):
 
     def test_start(self):

tests/test_runner.py

@@ -3,8 +3,7 @@ import os.path as osp
 import sys
 import tempfile
 import warnings
-
-from mock import MagicMock
+from unittest.mock import MagicMock
 
 sys.modules['wandb'] = MagicMock()
 
@@ -59,6 +58,6 @@ def test_wandb_hook():
         })
     runner.register_hook(hook)
     runner.run([loader, loader], [('train', 1), ('val', 1)], 1)
-    hook.wandb.init.assert_called()
+    hook.wandb.init.assert_called_with()
     hook.wandb.log.assert_called_with({'accuracy/val': 0.98}, step=5)
-    hook.wandb.join.assert_called()
+    hook.wandb.join.assert_called_with()