I have a big plastic tub that I fill with water and pump it up into the tank with a powerhead. I can leave a heater in to get it up to the right temp, but obviously not as neat as a python.
get about 5 feet of hose pipe and do a siphon you know suck till the water just about gets to your mouth then push the hose into the tank note: the water level in the tank your siphoning from must be higher up than the tank your filling
Was due a 10% change last night and planned to use a bucket. But after four days of zero ammonia and nitrite readings the nitrite started climbing so I did a 40% change and opted for the hosepipe which worked just fine. This evening I did a 10% change with a bucket which also worked fine. The tank is deep enough that I could pour it in slowly enough not to disturb the sand or plants but fast enough not to break my arms.
If a topping up is needed i use a stainless steel cooking pot. But that rarely ever happens. Because of the frequency of my water changes the tanks are always topped. I use a homemade Python for water changes.