I have this sparse vector val with this Pythonic ways:

idx = [2, 5, 6]
val = [69, 12, 15]

_ = np.zeros(idx[-1])

# This is not numpythonic because still using `for` syntax.
for i in range(len(idx)):
  _[idx[i]-1 : idx[i]+1] = val[i]

Here is the output:

[ 0. 69. 69.  0. 12. 15.]
(6,)
float64

How do I achieve my goals where it’s not using for loops, instead using numpythonic way?