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
– musically_ut, Commented Sep 2, 2015 at 8:28
stackoverflow.com/questions/986006/… u will get detail from here about pass by reference in python. — hizbul25
– hizbul25, Commented Sep 2, 2015 at 8:35

Hooting · Accepted Answer · 2015-09-02 08:37:18Z

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 2, 2015 at 8:37

Hooting

1,72111 silver badges20 bronze badges

Sign up to request clarification or add additional context in comments.

1 Answer 1