NameError oddity, undefined python variable reference

[Teriks]

In 1.0.4 I noticed this odd traceback for an undefined identifier.

I am using python 3.12.3

import asteval

interpreter = asteval.Interpreter()

interpreter.eval('i_dont_exist', raise_errors=True)

Output:

REDACT\venv\Scripts\python.exe REDACT\test.py 
Traceback (most recent call last):
  File "REDACT\venv\Lib\site-packages\asteval\asteval.py", line 293, in run
    ret = handler(node)
          ^^^^^^^^^^^^^
  File "REDACT\venv\Lib\site-packages\asteval\asteval.py", line 513, in on_name
    return self._getsym(node)
           ^^^^^^^^^^^^^^^^^^
  File "REDACT\venv\Lib\site-packages\asteval\asteval.py", line 505, in _getsym
    self.raise_exception(node, exc=NameError, msg=msg)
  File "REDACT\venv\Lib\site-packages\asteval\asteval.py", line 242, in raise_exception
    raise exc(self.error_msg)
NameError: name 'i_dont_exist' is not defined

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "REDACT\venv\Lib\site-packages\asteval\asteval.py", line 293, in run
    ret = handler(node)
          ^^^^^^^^^^^^^
  File "REDACT\venv\Lib\site-packages\asteval\asteval.py", line 356, in on_expr
    return self.run(node.value)  # ('value',)
           ^^^^^^^^^^^^^^^^^^^^
  File "REDACT\venv\Lib\site-packages\asteval\asteval.py", line 299, in run
    self.raise_exception(node, expr=expr)
  File "REDACT\venv\Lib\site-packages\asteval\asteval.py", line 242, in raise_exception
    raise exc(self.error_msg)
NameError: name 'i_dont_exist' is not defined

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "REDACT\venv\Lib\site-packages\asteval\asteval.py", line 293, in run
    ret = handler(node)
          ^^^^^^^^^^^^^
  File "REDACT\venv\Lib\site-packages\asteval\asteval.py", line 432, in on_module
    out = self.run(tnode)
          ^^^^^^^^^^^^^^^
  File "REDACT\venv\Lib\site-packages\asteval\asteval.py", line 299, in run
    self.raise_exception(node, expr=expr)
  File "REDACT\venv\Lib\site-packages\asteval\asteval.py", line 242, in raise_exception
    raise exc(self.error_msg)
NameError: name 'i_dont_exist' is not defined

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "REDACT\venv\Lib\site-packages\asteval\asteval.py", line 337, in eval
    return self.run(node, expr=expr, lineno=lineno, with_raise=raise_errors)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "REDACT\venv\Lib\site-packages\asteval\asteval.py", line 299, in run
    self.raise_exception(node, expr=expr)
  File "REDACT\venv\Lib\site-packages\asteval\asteval.py", line 242, in raise_exception
    raise exc(self.error_msg)
NameError: name 'i_dont_exist' is not defined

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "REDACT\test.py", line 7, in <module>
    interpreter.eval('i_dont_exist', raise_errors=True)
  File "REDACT\venv\Lib\site-packages\asteval\asteval.py", line 343, in eval
    raise self.error[-1].exc(errmsg) from exc
                                          ^^^
NameError: name 'exc' is not defined. Did you mean: 'exec'?

Process finished with exit code 1

Seems there is a reference to an undefined python variable in this case.

Perhaps it needs: except Exception as exc: in the handlers, it seems this error is possible in two places when looking at eval

def eval(self, expr, lineno=0, show_errors=True, raise_errors=False):
    """Evaluate a single statement."""
    self.lineno = lineno
    self.error = []
    self.start_time = time.time()
    if isinstance(expr, str):
        try:
            node = self.parse(expr)
        except Exception:
            errmsg = exc_info()[1]
            if len(self.error) > 0:
                lerr = self.error[-1]
                errmsg = lerr.get_error()[1]
                if raise_errors:
                    raise lerr.exc(errmsg) from exc # HERE exc does not exist
            if show_errors:
                print(errmsg, file=self.err_writer)
            return None
    else:
        node = expr
    try:
        return self.run(node, expr=expr, lineno=lineno, with_raise=raise_errors)
    except:
        errmsg = exc_info()[1]
        if len(self.error) > 0:
            errmsg = self.error[-1].get_error()[1]
        if raise_errors:
            raise self.error[-1].exc(errmsg) from exc # HERE exc does not exist
        if show_errors:
            print(errmsg, file=self.err_writer)
    return None

[newville]

@Teriks Thanks, and sorry for the trouble. #129 and #131 were similar issues.

Apparently, having sensible exceptions and reasonable handling of raise_errors is right at the threshold of my ability to do well ;)

I've updated the code and added a test so that this should now work. I'll choose to be cautiously optimistic but maybe not completely confident this is the end of it ;)

[newville]

@Teriks this should now be fixed, and in version 1.0.5, so closing.