Burmese pushing me away

[Boomer151]

My snake when i go to pet it to let it know im there. Pushes me away with its body, i know it sounds weird since they have no limbs but it like pushes off my hand, i can most of the time pick him up with no problem but it startles me when he does that because im not expecting it at all. Am i doing something wrong? Can someone teach me the right way to approach a burmese python for handling, ive had him for like a week, hes about four feet long and healthy