Is there any method to connect to vpn through python and have that traffic of that application only route through the said VPN?
Please, be more specific in your question. Generally, yes, it is possible.
If you use python 2.7 or newer, you can use source_address option for http connections (see reference for libraries you use) as tuple ('interface address', port).
If you use sockets in your app, use socket.bind(('interface address', port)) on created socket before socket.connect().
routing a only specific traffic through a vpn connection via python