Extract elements from numpy array, that are not in list of indexes

Question

I want to do something similar to what was asked here NumPy array, change the values that are NOT in a list of indices, but not quite the same.

Consider a nump

Answer 1

One way is to use a boolean mask and just invert the indices to be false:

mask = np.ones(a.size, dtype=bool)
mask[indxs] = False
a[mask]