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I am having trouble getting your script to run using Python 3.6.0. Please bear with me as I am not a programmer but the error I keep getting is

Traceback (most recent call last):
File "C:\Users\kd5jb\Downloads\opyscad-master\uploads-40-ea-52-c9-d1-canon_ef_extension_tube.py", line 164, in
res = tube(tube_in_radius, tube_out_radius, tube_height, tube_notch_size)
File "C:\Users\kd5jb\Downloads\opyscad-master\uploads-40-ea-52-c9-d1-canon_ef_extension_tube.py", line 63, in tube
notch /= [0, 0, angle]
TypeError: unsupported operand type(s) for /=: 'AbstractIns' and 'list'

Am I doing something wrong? I would love to be able to make some different tubes as they fit my 350D and lenses perfectly. Please advise.