mmcv安装卸载：ModuleNotFoundError: No module named 或者 WARNING: Skipping mmcv as it is not installed.

运行mmdetection时：
报错提示：

Traceback (most recent call last):
  File "tools/test.py", line 12, in <module>
    from mmdet.apis import multi_gpu_test, single_gpu_test
  File "d:\a文件盘\a项目\cv\mmdetection-master\mmdet\__init__.py", line 25, in <module>
    f'MMCV=={mmcv.__version__} is used but incompatible. ' \
AssertionError: MMCV==1.1.0 is used but incompatible. Please install mmcv>=1.0.5, <=1.0.5.
mmcv

版本需要为1.0.5，而自己默认安装的是1.1.0版本的。

先卸载mmcv

pip uninstall mmcv
pip uninstall mmcv-full

再安装mmcv版本为1.0.5：

pip install mmcv==1.0.5