Pass references to a python function

Question

In this example (which does not work)

def foo(x,y):
   x = 42
   y = y * 2

x = 0
y = 2
foo(x,y)

I would like x = 42 and y = 4.

The idea behind is to have a wrapper to C functions using ctypes:

def foo(self, x, y):
    error = self.dll.foo(self.handler, x, pointer(y))
    if error: 
       self.exception(error)

How can I pass parameters as references in Python?

You cannot pass primitive values by reference, unless you wrap or _box_ the variables into non-primitive objects (i.e., classes or lists) which are always passed by references. — musically_ut, Sep 02 '15 at 08:28
http://stackoverflow.com/questions/986006/how-do-i-pass-a-variable-by-reference u will get detail from here about pass by reference in python. — hizbul25, Sep 02 '15 at 08:35

score 3 · Accepted Answer · answered Sep 02 '15 at 08:37

3

Like @musically_ut, you cannot pass primitive values by reference, but you can get newest values by returning from function. Like this:

def foo(x,y):
   x = 42
   y = y * 2
   return x,y

x = 0
y = 2
x,y=foo(x,y)

answered Sep 02 '15 at 08:37

Hooting

1 Answers1