Re: [f2py] incompatible parameter transfer between python and fortran?

Xavier Barthelemy wrote (Tuesday 02 November 2010 07:24:15):
> > Please note that this cannot work because of how Python does things
> > You are passing an object of type integer to some function.  And as
> > integers are immutable, the object cannot be changed.  Python passes
> > by object, not by value.
> 
> hi Juergen
> What do you mean exactly?
> how is the correct form to pass these values? what kind have they to be?

This is a subtle subject.  Try a simple pure python example:

def f(x):
   x = 5

a = 7
f(a)
print a

In f(), the line "x = 5" lets the name x refer to a new object,
without changing the original object, which is still refered to by a
in the caller.


For f2py, you could get the intended behavior by using

a = array(7.)
f(a)

but that is not quite robust.


Juergen