The snub-nosed Python makes an appearance in the singleplayer mission "Payback," when Woods and Mason are forced to play Russian Roulette. Mason uses this revolver to kill the Viet Cong Bookie and takes his CZ75, but does not keep the Python, presumably because it only contained one round in the first place.
The snub nose is an attachment for the Python in multiplayer, costing 1000 CoD Points. The snub nose will increase the Python's centerspeed to 1800 instead of 1500, making the Python exceptionally more accurate. However, the maximum damage is lowered by 10, making the Python incapable of two shot kills up close without the use of a Headshot. This effectively ruins the Python's niche as a high-powered weapon up close, as the Python's power up close can be matched by other pistols. However, this effect can be exceptionally useful in Hardcore game modes, as the Python's power in Hardcore game modes is unaffected by the attachment, making the Snub Nose purely beneficial in Hardcore game modes. The Snub Nose makes the Python much more effective at range as a whole, as it doesn't have any downside to the damage at a distance. Overall, the Snub Nose is a somewhat odd choice of an attachment, but can work wonders on the Python in Hardcore game modes.
Four snub-nosed Pythons appear in the opening cutscene for Mob of the Dead. Billy Handsome is first seen with them, giving them out to the other mobsters, claiming to have stolen it from the warden's private collection. The mobsters use the Snub Nose Python's briefly afterwards to kill an undead Stanley Ferguson, although using a hefty amount of ammunition to do so.