Editing NumPy (section)

=== F2PY ===
Quickly wrap native code for faster scripts.<ref>{{cite web |title=F2PY docs from NumPy |url=https://numpy.org/doc/stable/f2py/usage.html?highlight=f2py |publisher=NumPy |access-date=18 April 2022}}</ref><ref>{{cite web |last1=Worthey |first1=Guy |title=A python vs. Fortran smackdown |url=https://guyworthey.net/2022/01/03/a-python-vs-fortran-smackdown/ |website=Guy Worthey |date=3 January 2022 |publisher=Guy Worthey |access-date=18 April 2022}}</ref><ref>{{cite web |last1=Shell |first1=Scott |title=Writing fast Fortran routines for Python |url=https://sites.engineering.ucsb.edu/~shell/che210d/f2py.pdf |website=UCSB Engineering Department |publisher=University of California, Santa Barbara |access-date=18 April 2022}}</ref>

<syntaxhighlight lang="fortran">
! Python Fortran native code call example
! f2py -c -m foo *.f90
! Compile Fortran into python named module using intent statements
! Fortran subroutines only not functions--easier than JNI with C wrapper
! requires gfortran and make
subroutine ftest(a, b, n, c, d)
  implicit none
  integer, intent(in)  :: a, b, n
  integer, intent(out) :: c, d
  integer :: i
  c = 0
  do i = 1, n
    c = a + b + c
  end do
  d = (c * n) * (-1)
end subroutine ftest
</syntaxhighlight>
<syntaxhighlight lang="pycon">
>>> import numpy as np
>>> import foo
>>> a = foo.ftest(1, 2, 3)  # or c,d = instead of a.c and a.d
>>> print(a)
(9,-27)
>>> help("foo.ftest")  # foo.ftest.__doc__
</syntaxhighlight>