I have read several articles on it. This is the popular belief on most of the posts about it.
Reticulated Python Breeding
Reticulated Pythons reach their sexual maturity anywhere between 7 and 12 feet or in as little as 18 months for males. Females however take much longer and are often unwilling to breed until they reach the age of 4 or 5. It is recommended to stop all feeding a minimum of 2 weeks before this begins in order to get any previously undigested food out of the snake. Animals should have excellent weight and be established before any breeding is attempted. Retics can be cooled in the low 70's during autumn. This temperature drop is to be achieved gradually in order to reduce the stress on the snakes body and to avoid any respiratory infections. During this period it is an ideal time to reduce the daylight time they receive to around 9 hours in order to simulate natural winter daylight conditions.
After 4 - 5 weeks the male and female can be placed together at the cooler temperatures and mist the cage for a couple of weeks. This is done by adding the female to the males cage, as this simulates the female entering the males territory as she looks for a mate. There must never be another male in the same cage as they can and will fight causing injuries to each other that often lead to death. After the introduction you will hopefully observe some copulation. Copulation can sometimes occur only at night. After the 3 weeks the retics should be separated. In comparison to other pythons the copulation procedure is relatively short with breeding lasting under half an hour each time and only occurring 3 - 5 times. After 45-60 days (approx.) she will have a pre-lay shed. You then have a further month or so to wait to see what she will lay. Females will generally lay between 25-80 eggs but numbers above this have been recorded. This number is affected by the number of times she has been bred before, how old she is and how big she is.