WARNING: Retrying (Retry(total=4, connect=None,
1. 故障描述
问题：在使用python时，我们经常需要安装一些包，但是在终端prompt或者cmd界面下，使用pip install xxx（包）的时候，可能会出现如下的报错信息：
WARNING: Retrying (Retry(total=4, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError(SSLEOFError(8, 'EOF occurred in violation of protocol (_ssl.c:1131)'))': /simple/bista/
WARNING: Retrying (Retry(total=3, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError(SSLEOFError(8, 'EOF occurred in violation of protocol (_ssl.c:1131)'))': /simple/bista/
WARNING: Retrying (Retry(total=2, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError(SSLEOFError(8, 'EOF occurred in violation of protocol (_ssl.c:1131)'))': /simple/bista/
WARNING: Retrying (Retry(total=1, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError(SSLEOFError(8, 'EOF occurred in violation of protocol (_ssl.c:1131)'))': /simple/bista/
WARNING: Retrying (Retry(total=0, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError(SSLEOFError(8, 'EOF occurred in violation of protocol (_ssl.c:1131)'))': /simple/bista/
Could not fetch URL https://pypi.org/simple/bista/: There was a problem confirming the ssl certificate: HTTPSConnectionPool(host='pypi.org', port=443): Max retries exceeded with url: /simple/bista/ (Caused by SSLError(SSLEOFError(8, 'EOF occurred in violation of protocol (_ssl.c:1131)'))) - skipping
ERROR: Could not find a version that satisfies the requirement bista (from versions: none)
ERROR: No matching distribution found for bista
2. 问题解决
调用国内的源镜像，并信任指定的源
国内的pip源：
- 阿里云 http://mirrors.aliyun.com/pypi/simple/
- 中国科技大学 https://pypi.mirrors.ustc.edu.cn/simple/
- 豆瓣(douban) http://pypi.douban.com/simple/
- 清华大学 https://pypi.tuna.tsinghua.edu.cn/simple/
- 中国科学技术大学 http://pypi.mirrors.ustc.edu.cn/simple/
标准示意代码如下：
pip install xxx -i http://mirrors.aliyun.com/pypi/simple --trusted-host mirrors.aliyun.com