Can an object inspect the name of the variable it’s been assigned to?

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Yes, it is possible*. However, the problem is more difficult than it seems upon first glance:

  • There may be multiple names assigned to the same object.
  • There may be no names at all.
  • The same name(s) may refer to some other object(s) in a different namespace.

Regardless, knowing how to find the names of an object can sometimes be useful for debugging purposes – and here is how to do it: 

import gc, inspect

def find_names(obj):
    frame = inspect.currentframe()
    for frame in iter(lambda: frame.f_back, None):
        frame.f_locals
    obj_names = []
    for referrer in gc.get_referrers(obj):
        if isinstance(referrer, dict):
            for k, v in referrer.items():
                if v is obj:
                    obj_names.append(k)
    return obj_names

If you’re ever tempted to base logic around the names of your variables, pause for a moment and consider if redesign/refactor of code could solve the problem. The need to recover an object’s name from the object itself usually means that underlying data structures in your program need a rethink.

* at least in Cpython

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