'read only' closures in python

test.js

function outer () {
   var foo = 'yellow';
   function inner () {
      foo = 'blue';
   }
   function out () {
      console.log(foo);
   }
   return [inner, out];
}

var result = outer();
var inner = result[0];
var out = result[1];

out();
inner();
out();

// $ node test.js 
// yellow
// blue

test.py

def outer ():
    foo = 'yellow'
    def inner ():
        foo = 'blue'          # this `foo` is local to the function `inner()`
    def out ():
        print foo             # this `foo` is the `foo` defined on line 2
    return inner, out

inner, out = outer()

out()
inner()
out()

# $ python test.py
# yellow
# yellow