$$\max \lbrace 0, q_i \rbrace \le L^r_i \le \min \lbrace Q^r,Q^r+q_i \rbrace \quad \forall i\in N,r\in R$$
I am not sure if this type of question is allowed here but I am stuck at modeling this constraints for the pickup dropoff problem with time window in Python using Gurobi API. Can anyone point me in the right direction or show an example?