TypeError: slice indices must be integers or None or have an __index__ method

when i run " ./view_steering_model.py ./outputs/steering_model/steering_angle.json", it prompt me this error message:
Traceback (most recent call last):
File "./view_steering_model.py", line 120, in
draw_path_on(img, speed_ms, -angle_steers/10.0)
File "./view_steering_model.py", line 84, in draw_path_on
draw_path(img, path_x, path_y, color)
File "./view_steering_model.py", line 59, in draw_path
draw_pt(img, x, y, color)
File "./view_steering_model.py", line 55, in draw_pt
img[row-sz:row+sz, col-sz:col+sz] = color
TypeError: slice indices must be integers or None or have an __index__ method
How to solve this problem?