Class UndefinedVariableError

pandas/errors/__init__.py:718–755

Exception raised by ``query`` or ``eval`` when using an undefined variable name. It will also specify whether the undefined variable is local or not. Parameters ---------- name : str The name of the undefined variable. is_local : bool or None, optional Indi

class UndefinedVariableError(NameError):
    """
    Exception raised by ``query`` or ``eval`` when using an undefined variable name.

    It will also specify whether the undefined variable is local or not.

    Parameters
    ----------
    name : str
        The name of the undefined variable.
    is_local : bool or None, optional
        Indicates whether the undefined variable is considered a local variable.
        If ``True``, the error message specifies it as a local variable.
        If ``False`` or ``None``, the variable is treated as a non-local name.

    See Also
    --------
    DataFrame.query : Query the columns of a DataFrame with a boolean expression.
    DataFrame.eval : Evaluate a string describing operations on DataFrame columns.

    Examples
    --------
    >>> df = pd.DataFrame({"A": [1, 1, 1]})
    >>> df.query("A > x")  # doctest: +SKIP
    ... # UndefinedVariableError: name 'x' is not defined
    >>> df.query("A > @y")  # doctest: +SKIP
    ... # UndefinedVariableError: local variable 'y' is not defined
    >>> pd.eval("x + 1")  # doctest: +SKIP
    ... # UndefinedVariableError: name 'x' is not defined
    """

    def __init__(self, name: str, is_local: bool | None = None) -> None:
        base_msg = f"{name!r} is not defined"
        if is_local:
            msg = f"local variable {base_msg}"
        else:
            msg = f"name {base_msg}"
        super().__init__(msg)


class IndexingError(Exception):