Retrieving the list of references to an object in Python

Question

All:

a = 1
b = a
c = b

Now I want to get a list of object 1 tagged, which is [a, b, c]. How could I do this?

Answer 1

I'd like to clarify some misinformation here. This doesn't really have anything to do with the fact that "ints are immutable". When you write a = 2 you are assigning a and a alone to something different -- it has no effect on b and c.

If you were to modify a property of a however, then it would effect b and c. Hopefully this example better illustrates what I'm talking about:

>>> a = b = c = [1]  # assign everyone to the same object
>>> a, b, c
([1], [1], [1])
>>> a[0] = 2         # modify a member of a
>>> a, b, c
([2], [2], [2])      # everyone gets updated because they all refer to the same object
>>> a = [3]          # assign a to a new object
>>> a, b, c
([3], [2], [2])      # b and c are not affected