Python 出现错误 SNIMissingWarning: An HTTPS request has been made, but the SNI (Subject Name Indication) extension to TLS is not available on this platform.

报出SNIMissingWarning和InsecurePlatformWarning警告。

解决方法：

　　

在cmd中输入：

　　pip install pyopenssl ndg-httpsclient pyasn1