Off-topic, but maybe as practical as "[making] your own Python build from altered source." ---
Fortran 95 (and earlier versions) has single and double precision floats. One could write a Fortran code with variables declared REAL, and compilers will by default treat the REALs as single precision, but most compilers have an option to promote single precision variables to double. In Fortran 90+ one can specify the KIND of a REAL, so if variables as REAL (kind=rp) :: x,y,z throughout the code with rp being a global parameter, and one can switch from single to double by changing rp from 4 to 8. G95 is a good, free compiler. F95 has most but not all of the array operations of NumPy. -- http://mail.python.org/mailman/listinfo/python-list
