You can also take a cab. Czech taxi services generally don’t have a good reputation, and that is the opinion of many locals. One common complaint is that the drivers will try to exploit the assumed ignorance of their fare. This is definitely one of the occasions when speaking Czech is an advantage. As for price, I remember, vaguely, one cab ride from Malá Strana to Vinohrady costing about 180 CZK, and the driver took a direct route.