pip install pyperclip 安装失败，问题定位：Python模块无法越过企业防火墙直接使用

  Retrying (Retry(total=0, connect=None, read=None, redirect=None)) after connec
tion broken by 'ProxyError('Cannot connect to proxy.', OSError('Tunnel connectio
n failed: 407 authenticationrequired',))': /simple/pyperclip/
  Could not find any downloads that satisfy the requirement pyperclip

  No distributions at all found for pyperclip

试定位：

1.pip版本不对  X

2.pyperclip安装源不对 pip install -i URL  X

解决办法：https://stormpoopersmith.com/2012/03/20/using-applications-behind-a-corporate-proxy/