0 day streak0 XPP1
Write a function. Test real cases. Improve your solution.
Return a list showing the change from each reading to the reading immediately before it: current minus previous. The first result is always None because it has no previous reading. If either of the two neighboring readings is None, that change is also None. Do not skip over missing readings. An empty input returns an empty list. Readings are integers or None; leave the input unchanged.
[[4, 7, 5]]
[None, 3, -2]
[[0, 0, 2]]
[None, 0, 2]
[[10, None, 14, 19]]
[None, None, None, 5]
[[-5, -8, -8]]
[None, -3, 0]
[[]]
[]
[[3]]
[None]
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