> Personally, I think it's more important to be able to read
> scientific data easily without too many problems, then to be
> able to write the processed data in exactly the same way it
> was read.

I wonder whether there are many examples where scientific data is written in a form that Python's complex() constructor couldn't currently read, but would be able to read if it accepted 'i' in place of 'j'.

My (wild) guess would be that, in the cases where the data isn't stored in binary form anyway, complex numbers are written simply as pairs of floats.