This PR is stale because it has been open for 30 days with no activity.

Why do I think the error message is fine as is, mentioning the delete aspect doesn't sit so well with me, I mean the actual state is that the variable is unbound, which is standard enough. I don't know what @vstinner thinks of this?

Well, the current message doesn't just say the variable is unbound. It says " local variable 'x' referenced before assignment", which is incorrect in my example.

Why do I think the error message is fine as is, mentioning the delete aspect doesn't sit so well with me, I mean the actual state is that the variable is unbound, which is standard enough. I don't know what @vstinner thinks of this?

Well, the current message doesn't just say the variable is unbound. It says " local variable 'x' referenced before assignment", which is incorrect in my example.

I see what you mean but my reasoning is, "before assignment" is kind of a synonym for unbound, which sort of makes sense to me, no?

I see what you mean but my reasoning is, "before assignment" is kind of a synonym for unbound, which sort of makes sense to me, no?

We could do something like ‘using an unassigned variable’ if that sound better.

English is not my first language, so I let the others decide. I approved the PR since it fix an issue and it's correct ;-)

I would prefer to use something generic that doesn't refer to any specific operation as there are other ways to trigger this that are not technically assignments or deletions. FOr example:

>>> def blech(x):
...    print(lel)
...    import lel
...
>>> blech(3)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<stdin>", line 2, in blech
UnboundLocalError: local variable 'lel' referenced before assignment

I agree, how about one of these?

UnboundLocalError: local variable 'lel' is not associated with a value

UnboundLocalError: reading undefined local variable 'lel'

I agree, how about one of these?

UnboundLocalError: local variable 'lel' is not associated with a value

UnboundLocalError: reading undefined local variable 'lel'

I personally think that these are still quite confusing. For example:

UnboundLocalError: reading undefined local variable 'lel'

I think people will still be confused with the message given that in:

x = 4
def foo():
    print(x)
    x = 3

they think the variable is defined.

UnboundLocalError: local variable 'lel' is not associated with a value

Same as before, people can still think that the variable is associated with a value later.

Maybe we could modify this slightly to:

UnboundLocalError: local variable 'lel' is not associated with a value at the time it was accessed

Maybe is too verbose....

UnboundLocalError: local variable 'lel' is not associated with a value at the time it was accessed

Shorter:

UnboundLocalError: accessed local variable 'lel' where it is not associated with a value

UnboundLocalError: local variable 'lel' is not associated with a value at the time it was accessed

Shorter:

UnboundLocalError: accessed local variable 'lel' where it is not associated with a value

Looks great!

I noticed another message just below for free variables - I think the same applied there -- see this unit test

@pablogsal @nanjekyejoannah Are we all good here?

Are we all good here?

Ok from me 👍