try/finally - what is Python doing to the local namespace on an exception?

This is not a duplicate of the various why does a finally suppress my exception questions.

Instead, I find that finally's local variables are unexpected, but only in the case of an exception. In that case, the exception disappears.

(This is on Python 3.8)

def test(divisor):
    print(f"\n\ntest({divisor=})")
    exc = None  #  always assigned!
    foo = 1

    print(f"  ante.{exc=}")

    try:
        _ = 1 / divisor
        print(f"  post.{exc=}")


    except (Exception,) as exc: 
        print(f"  except.{exc=}")
    else:
        print(f"  else.{exc=}")
    finally:
        print(f"  finally:{locals()=}")

        #at this point, it should be either None 
        #whatever was caught in the except clause
        print(f"  finally.{exc=}")

test(1)

test(0)

Output in the case of success - as expected:

test(divisor=1)
  ante.exc=None
  post.exc=None
  else.exc=None
  finally:locals()={'divisor': 1, 'exc': None, 'foo': 1, '_': 1.0}
  finally.exc=None

On an exception - UnboundLocalError

It looks like the local namespace had exc deleted and this causes an UnboundLocalError error.

I'd expect it to have the ZeroDivisionError. At most, if except was defining a local scope for some reason, it could be still be None. But it's just gone.

as if del locals()["exc"] had taken place.

test(divisor=0)
  ante.exc=None
  except.exc=ZeroDivisionError('division by zero')
  finally:locals()={'divisor': 0, 'foo': 1}
Traceback (most recent call last):
  File "test_195_finally.py:27", in <module>
    test(0)
  File "test_195_finally.py:23", in test
    print(f"  finally.{exc=}")
UnboundLocalError: local variable 'exc' referenced before assignment

Binding exc to another variable shows that other variable is alive and well.

    except (Exception,) as exc: 
        exc2=exc

  finally:locals()={'divisor': 0, 'foo': 1, 'exc2': ZeroDivisionError('division by zero')}