Forty-seven-year old, Sue Cull of Griffith John Street, Swansea, was on her way home from a pub when she was bitten by a python.
She was in an area which is many thousands of miles form the snake's natural habitat in the tropics.
She was on her way to pick up a takeaway curry and needed to cross a patch of grass. At Morriston hospital, where she availed treatment, they had not quite seen any patient with a python bite and needed to take advice from a reptile and venom unit in London.
A spokesman for the Reptile Centre in Cardiff said: "It is possible she had an allergic reaction. Any snake may bite if it is frightened but the bite alone will not kill you."
Recounting the horror, Sue said, "It's just bizarre - when you are walking around you don't think there is going to be a python attacking you. If we had been told by police there was a snake on the loose I wouldn't have walked through the grass. I'm just lucky the snake didn't constrict me as well."