You will need to adjust your conda configuration to proceed.解决办法

最近要用python2.7的，安装虚拟环境时发生了下边的错误：

CondaHTTPError: HTTP 404 NOT FOUND for url <https://pypi.doubanio.com/simple/noarch/repodata.json>
Elapsed: 00:00.124769

The remote server could not find the noarch directory for the
requested channel with url: https://pypi.doubanio.com/simple

As of conda 4.3, a valid channel must contain a `noarch/repodata.json` and
associated `noarch/repodata.json.bz2` file, even if `noarch/repodata.json` is
empty. please request that the channel administrator create
`noarch/repodata.json` and associated `noarch/repodata.json.bz2` files.
$ mkdir noarch
$ echo '{}' > noarch/repodata.json
$ bzip2 -k noarch/repodata.json

You will need to adjust your conda configuration to proceed.
Use `conda config --show channels` to view your configuration's current state.
Further configuration help can be found at <https://conda.io/docs/config.html>.

发现镜像未经授权，也就是说，需要回复到官方源镜像，恢复镜像命令：

conda config --remove-key channels

可以切换国内其他源镜像：

　　　　添加源命令：

conda config --add channels

可添加国内镜像 例：

　　清华源镜像：

#添加清华的源
conda config --add channels https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/free/

中科大的源镜像：

conda config –add channels https://mirrors.ustc.edu.cn/anaconda/pkgs/free/ 

阿里云的源镜像：

conda config --add channels http://mirrors.aliyun.com/pypi/simple/

我添加清华镜像后下载速度，飞升

参考博客：https://blog.csdn.net/yixieling4397/article/details/100551813

　　　　　https://www.jianshu.com/p/1a2b0976cd1a