The Colt Python is the most accurate pistol and only revolver available in the GTA series. It also shares the record for being the most powerful pistol with the Desert Eagle, although the Desert Eagle edges it out, being a .50AE instead of a .357.
The Colt Python was first seen in Grand Theft Auto: Vice City. The gun cannot be fired while running, and must be fired from a Weaver position (grasping the butt of the gun with the right hand, then cradling the right hand and gun with the cupped left hand, all while planting feet at a wide stance) due to the heavy recoil of the .357 Magnum cartridge. It also has a moderate cylinder capacity of 6 shots, making it excellent against small groups. The Python is also available in Grand Theft Auto: Liberty City Stories, and the version in Grand Theft Auto: Vice City Stories (named Equalizer) features a laser scope and a 6" barrel, although the scope cannot be used.
The Colt Python is also a weapon in Grand Theft Auto: Chinatown Wars, and was named the Revolver. Although it cannot be visibly seen in the game, a HUD image of the weapon can be seen on the touch screen and on the Ammu-Nation website (strangely, it resembles a snub-nosed .38 Smith and Wesson or a Colt Detective Special).