CODEWITHSUNDEEP
pythonclasspointers
user3147172
user3147172

Reputation: 11

In Python, how to "point" to an outside object within a class?

In Python, I have a 

class OBJECT

that is initialized. I am now creating a new class that will need to use methods of this object. If I do:

class NEW_CLASS:
      def __init__(self, Object):
            self.Object = Object

NEW_CLASS(OBJECT)

Does self.Object work like a pointer (excuse the terminology, originally a C programmer) where it points to OBJECT (my desired result) or does self.Object create a separate OBJECT within NEW_CLASS? If it doesn't act like a pointer, how can I implement this behavoir?

I will have one OBJECT in my project but many NEW_CLASS and NEW_CLASS will need to access OBJECT. I don't want to create a new copy for each NEW_CLASS.

Thanks for the help!

Upvotes: 1

Views: 221

Answers (3)

Bleeding Fingers
Bleeding Fingers

Reputation: 7129

No doubt it is the same of object. And they both have the same id, meaning memory location in C/C++.

>>> id(NEW_CLASS(OBJECT).Object) == id(OBJECT)
True

id(...)
    id(object) -> integer

    Return the identity of an object.  This is guaranteed to be unique among
    simultaneously existing objects.  (Hint: it's the object's memory address.)

One advice, avoid using object(irrespective of cases) as a variable name.

help(object)
class object
 |  The most base type

Upvotes: 0

Santa
Santa

Reputation: 11545

So, you want OBJECT to be a global object?

How about (stylized to follow Python conventions):

class GlobalObject:
    """Insert class definition here."""

OBJECT = GlobalObject()


class MyClass:
    def __init__(self, global_object=OBJECT):
        self._object = global_object

    def do_something():
        print "The object is: %s" % self._object

Upvotes: 0

Simeon Visser
Simeon Visser

Reputation: 122436

It will indeed behave as a pointer. So every time you access self.Object you'll be accessing the same Object that was initially passed to a new instance of the class NEW_CLASS.

Upvotes: 2

Related Questions