C++ is the language used to actually write the game, at least for the graphically-intensive complex games like World of Warcraft. Languages like Python are often used for scripting behaviors within the game.
On the other hand, a major category of games is the "casual" games category, which includes simpler games like Sudoku games or simple puzzle solving games. These might be written in a very high level language like Python.
More likely than Python, however, lightweight games are usually written in Flash, using the scripting language in Flash (ActionScript). It turns out that this is actually a flavor of Javascript. Javascript, in turn, is much like Python.
So, my suggestion is that you learn Python, and then learn Javascript. Then write some simple games in your choice of PyGame, Flash, or even in-browser Javascript. Then if you still want to learn C++, go on and learn that, but keep playing around with game design in your spare time, writing casual games.
