If you go to basketball-reference you can quickly (in under ten minutes) copy-and-paste entire careers of game logs into excel. It took me ten minutes for Kobe, and most people don't have as many game as him. Then, all you got to do is make a new column for shot attempts (fga+0.44*fta), make one for points per shot attempt (points/sa) and there you have it. I assume this is what you mean by weighted shots. If you want to take this a step further you can calculate extra points (the additional value of having player x shoot versus the average). Do this by subtracting the league average from player x's average ppsa, and then multiplying the difference by his shot attempts.