floating error while executing "Clone an Existing Dataless SEED File"

Hi Obspy users,
Getting following error,

Traceback (most recent call last):
File “clonedataless.py”, line 38, in
blk[58][i*mult].sensitivity_gain = 400.0
TypeError: list indices must be integers or slices, not float

i tried to resolve the issue while changing the flating value but still error is same.
i am using python3.7.

Your i*mult likely is a float, but since you use it as an index, its
supposed to be an integer. Older numpy was lenient about it. Newer numpy

Cast to int, whenever something computed on the fly is used to index