ball pythons routinely decide to go off food for months at a time, usually in the winter. it is nothing to worry about, it is just normal behavior.
i have 4 that have been off food for about 3 months,
i have heard of bps surviving and restarting eating after 11 months, so as long as there is no major drop in body weight, dont worry.
is is also a good idea to get your snake checked for worms, that is the other possible reason for them going off food. bring in a fecal sample to your local reptile vet, and ask them to check for worms. the sample has to be fresh though
good luck
oh and 1 mouse / week is no where near enough for an adult bp. if it is a young snake( within 8 months) it is fine. as a rule, the food item offered should be roughly the width of the widest part of your snakes body. my adult bps will eat 5 mice in one sitting, that is why i switched to rats.