Having a 2d numpy array, for example

data = np.ones((3, 5))

how can i create an boolean mask for this array for all elements of a row up to a specific index stored row-wise in another np.array. So the “end index” array looks like

np.array([0, 2, 3])

The output should look like:

[[True False False False False]
 [True True True False False]
 [True True True True False]]

I tried fancy indexing with a row and column array, but dont know how to specify the column ranges for each row.