I don't think anyone will argue, that reptiles don't have these feelings and express them. They avoid what they fear, attack what makes them angry, and seek out what is pleasurable. If you create an environment that is comfortable and pleasant, and you do things to your pet that make it feel comfortable and pleased, then the reptile will 'like' you in the sense that good things come from you, and therefore it wants to be with you. Whether reptiles have more complex feelings, like 'liking', is a hard question, and I would give a guarded 'yes' for chelonians, but I don't know about others. In order to like someone, the animal has to distinguish between people and clearly prefer some over others.
Chelonians do tell people apart, and they prefer some people over others.
I noticed to my surprise, that there are people my friendly snake does not like for no reason I can make out. He'll sit there for up to 15 minutes. In general, you can't potty train the animal. It will train you. Many reptiles follow a daily routine which also includes eliminating.