I think the frantic concern about Diamonds and suitable temperatures that seems rife at the moment is causing a lot of problems with newish keepers who think that Diamonds must be kept half warm in case they get something called DPS. This leads to ineffective heating strategies, compromised immune systems and resultant disease. When they do seek heat, they're not getting warm enough because new keepers think they should only be in the high twenties. This is a recipe for disaster for any python, especially in the cooler months. If keepers bothered to check the temperature maxima of the regions in which even the most southern Diamonds live, they would see that summer day temps, occasionally in the 40s, are not unusual (probably more common than we get further north on average). If you average the temps in those regions out, because nights are cooler, and winters a bit longer, you'll get a cooler average, and basing your temperature regimes on this cooler average is where the damage is done.
Even if they are offered heat for shorter periods, the heat that's available to Diamonds must be pretty much the same as that offered to any other python - a basking spot in the low to mid-thirties, and available for sufficient time to allow the whole body of the snake to warm properly for a few hours - maybe 4 hours winter, 6-8 hours summer. It's also good practice to reduce or stop handling in the cooler months, especially when the snake may be cold to touch - handling at this time is very disruptive and forces activity when the snake should be left to its own devices.
Jamie