CondaHTTPError: HTTP 404 NOT FOUND for url ＜https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main/

问题：CondaHTTPError: HTTP 404 NOT FOUND for url <https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main/win-64/python-3.7.0-hea74fb7_0.tar.bz2> Elapsed: 00:00.260600

解决办法：

在用户目录下（如win10中C:\Users\xxx\），修改.condarc文件，内容替换如下：

channels:
  - defaults
show_channel_urls: true
channel_alias: https://repo.anaconda.com
default_channels:
  - https://repo.anaconda.com/pkgs/main
  - https://repo.anaconda.com/pkgs/free
  - https://repo.anaconda.com/pkgs/r
  - https://repo.anaconda.com/pkgs/pro
  - https://repo.anaconda.com/pkgs/msys2
custom_channels:
  conda-forge: https://mirrors.tuna.tsinghua.edu.cn/anaconda/cloud
  msys2: https://mirrors.tuna.tsinghua.edu.cn/anaconda/cloud
  bioconda: https://mirrors.tuna.tsinghua.edu.cn/anaconda/cloud
  menpo: https://mirrors.tuna.tsinghua.edu.cn/anaconda/cloud
  pytorch: https://mirrors.tuna.tsinghua.edu.cn/anaconda/cloud
  simpleitk: https://mirrors.tuna.tsinghua.edu.cn/anaconda/cloud