Hello all, I have been trying to compile a relatively simple pair of Fortran files, one referencing a subroutine from another file (mainmodule.f90 references othermodule.f90). I have been able to compile them using a Fortran compiler, but receive a NotImplementedError when using f2py. Steps I use for f2py: $gfortran -shared -o othermodule.so othermodule.f90 -fPIC $f2py -c -l/path/othermodule -m mainmodule mainmodule.f90 I am running this on linux and wasn't sure how to correct the error. othermodule.f90 module moderator implicit none integer*1 :: i integer*8 :: fact,len real*8,dimension(:),allocatable :: ex contains subroutine submarine(ii,ff,exex) implicit none integer*1 :: ii integer*8 :: ff real*8 :: exex exex=exp(real(ii))/ff end subroutine submarine end module moderator mainmodule.f90 program mains use moderator implicit none len=10 allocate(ex(len)) fact=1 do i=1,len fact=fact*i call submarine(i,fact,ex(i)) if (i==1) then print*,"here's your ",i,"st number: ",ex(i) elseif (i==2) then print*,"here's your ",i,"nd number: ",ex(i) elseif (i==3) then print*,"here's your ",i,"rd number: ",ex(i) else print*,"here's your ",i,"th number: ",ex(i) endif enddo deallocate(ex) end program Thanks for the help, Andy