每当我尝试使用命令安装 ChatterBot 时，pip install ChatterBot都会出现以下错误：
Retrying (Retry(total=0, connect=None, read=None, redirect=None)) after connection broken by 'NewConnectionError('<pip._vendor.requests.packages.urllib3.connection.VerifiedHTTPSConnection object at 0x0000000003687898>: Failed to establish a new connection: [Errno 11001] getaddrinfo failed',)': /simple/chatterbot/
Could not find a version that satisfies the requirement chatterbot (from versi
ons: )
No matching distribution found for chatterbot
我从 Python 3.6 降级到 2.7，但收到相同的错误。
我使用的是 Windows 8、Anaconda 2.7