Problem: I want to write a function that randomly picks elements from a training set, based on the bin probabilities provided. I divide the set indices to 11 bins, then create custom probabilities for them. bin_probs = [0.5, 0.3, 0.15, 0.04, 0.0025, 0.0025, 0.001, 0.001, ... It is 1-D, it is integer, and it is scalar. What am I missing? Note : I tried to pass indices with astype(int). Same error.