I have resolved this issue while disconnected the VPN. One more thing, go to computer network connection and find proxy setting and turn off proxy setting and set the internet connection with automatic default.

Thank you very much for helping the community.

Your answer to that problem was very helpful, as I couldn't install Flask with the pip command (pip install Flask).

pip: ERROR: Could not install packages due to an OSError: Missing dependencies for SOCKS support.

Line: 1 Character: 1

+ pip install request -i http://pypi.douban.com/simple --trusted-host p ...

+ CategoryInfo: NotSpecified: (ERROR: Could no... SOCKS support.:String) [], RemoteException

+ FullyQualifiedErrorId: NativeCommandError

WARNING: There was an error checking the latest version of pip.