解决方法：在conda里一行行键入以下命令即可：
conda config --remove channels https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/free/
conda config --add channels https://repo.continuum.io/pkgs/free/
conda config --add channels https://repo.continuum.io/pkgs/main/
conda config --set show_channel_urls yes
