No snake will ever constrict as a defense either, they only constrict their food
Gotta disagree with you on that one. my Rosy Boa constricted my boyfriend's hand constantly during the "taming" period (it was a biter when we first got it). It was very feisty and would not let go for about 15 minutes. I KNOW it didn't see Chris as food. Also, it goes through non feeding periods but if I wiggle the mouse around enough it will still constrict it but not eat it. Almost as if to make sure it's dead, then he leaves it alone.
Depending on your experience level, a Ball Python, hog Island Boa, Rosy Boa, or Corn snake would be fine for you.