使用pip來安裝python包有時候安裝起來會非常慢，因此需要換成國內的源來加速下載：

使用命令

以Torch為例：

pip install -i https://pypi.tuna.tsinghua.edu.cn/simple torch

若無法連接

WARNING: The repository located at pypi.doubanio.com is not a trusted or secure host and is being ignored. If this repository is available via HTTPS we recommend you use HTTPS instead, otherwise you may silence this warning and allow it anyway with '--trusted-host pypi.doubanio.com'.

ERROR: Could not find a version that satisfies the requirement opencv-python (from versions: none)

ERROR: No matching distribution found for opencv-python

可以將源中的http改為https

需要user

Could not install packages due to an EnvironmentError: [Errno 13] Permission denied: '/anaconda3/lib/python3.7/site-packages/llvmlite-0.28.0.dist-info'

Consider using the --user option or check the permissions.

需要加上--user：pip install 改為 pip install --user

pip install --user -i https://pypi.tuna.tsinghua.edu.cn/simple torch

審核編輯 hhy