Comment by 098799

Nothing weird about it. It should be obvious that subtracting two floats that are very close to each other results in a loss of numerical precision:

1.000000003456e0 - 1.000000002345e0 = 0.000000001111e0 = 1.111numericalnoise e-9

It's exactly the same issue here. `math.exp(1e-15)` is `1.000000000000001`. If you subtract 1, you get 1 significant digit and numerical noise.