If you have a tabk at 80F and you do a 50% wc and lets assume the refill water is 5F above or below the tank temp, all your can chnage the temp by is 2.5F. Unless you are keeping the tank on the temp line close to where it will kill fish, that 2.5 change is meaningless. In the wild water tamps are rarely constant. They change with depth. There are very few fish who will suffer aything because their water temp changes by 2.5F.
Let's consider the fact that if we research the temperature conditions any fish requires we do not find a single number, we find a range. Fish in a lake move up and down in depth, they may swim through a inlflow from a spring which es very cold, these things do not kill it. Nightime water temps are often cooler than those during the day, etc.
And the science clear;y shows that if a fish is in a temperature, either cold or hot which would be fatal if they remain there for any time, they exhibit specific behaviors which precede death, the way to save the fish is to get it back into water which is in its normal temperature range ASAP. Do not acclimate it do not waste a minute, just get them into the right temp. This will not kill or harm them it, will save them.
I can tell you I have had practical experience with this and it is absolutely true that this is what must be done.
As for water changes. I do not use a Python. However I use their hoses and have all of their adapters for faucets. I do all garden hose size connectors incluidng om ny utility sink. Even my RO/DI unit uses them. But I pump almost all tank water both out and in. Despite having our own well and not needing to use dechlor, I batch my return water in big Rubbermade trash cans at a warm temp (86F) by the time it goes into tanks is will be cooler, maybe as low as 78F. The fish do not really care.
I pump water out either out a window or into a toilet. The season determines which as well as where the tank is located. In winter when the ground is frozen I cannot pump out windows. I do use buckets to remove water from any tank unde 20 gals. But that is because I rinse media in a bucket of tank water. That is the easiest way to do it. A 50% water change on a 10 gal. tank requires all of two buckets of 2.5 gals. Easy. But all tanks, even my tiny 5.5 gal. are refilled via pumping.
One reason I do things this way is I am old. When I got my first tank I could carry a filled 5 gal. bucket in each hand and carry them the length of the house. Not any more. Pumps are now a necessity rather than a convenience. Also, my tanks are spread out bey=tween 2 buildings and 4 -5 rooms depending on he season. I set up temporary summer tanks, basically outdoors but in the shade, which are only used for about 4.5 months and then taken down.
One last note. I am not willing to use regular garden hoses for tank refilling. These often contain anti-molding agents. All my refill hoses are drinking water grade. BTW- to clean a hose of the mung we cannot see but which is there, I connect the host to a pump, drop it into a bucket with water containing bleach and put the out put end of the hose into the bucket and run the pump for a while. Then I rinse it using clean water which goes down the drain.
I have come to love my pumps and hoses and so does my back......