It is a pity that such an operation will not work with an odd key))
Sure it will, if you add an odd key to another odd key ( our 2^256 key is odd ) you'll get an even key and all you have to do is to subtract the following key from the result :
a2a8918ca85bafe22016d0b997e4df5f
But why bother if you could add or subtract 1G from your odd key and divide it without having to do what I said.
You can always divide an odd key, if by 2, you'd have to add n/2 to the result, if by 3, adding n/3 etc to get your actual and correct result.
sorry my english is not good, i'm trying to understand by translating with translate, this gives me different sentences, so can you write the python code for the division you said.