pola-rs/polars · error · AttributeError

{objname} object has no attribute {name!r}

Error message

{objname} object has no attribute {name!r}

What it means

Fallback AttributeError raised by polars' getattr_fallback when a missing attribute is looked up on a polars class and no superclass __getattr__ handles it. It is the terminal error after removed-attribute checks have passed, producing the standard 'object has no attribute' message (with quoting adapted for metaclasses).

Source

Thrown at py-polars/src/polars/_utils/expired.py:87

    Raise an `AttributeError` for a non-existent attribute.

    Parameters
    ----------
    obj
        The object on which the attribute was accessed.
    superclass
        The superclass of the object used to attempt to access the attribute.
    name
        The name of the non-existent attribute.
    meta
        Whether the object is a metaclass (default: False).
    """
    if (super_getattr := getattr(superclass, "__getattr__", None)) is not None:
        return super_getattr(name)
    else:
        objname = f"{obj.__name__!r}" if meta else f"{type(obj).__name__!r}"  # type: ignore[attr-defined]
        msg = f"{objname} object has no attribute {name!r}"
        raise AttributeError(msg, name=name, obj=obj)


def removed_parameters(
    *params: RemovedParameter | RenamedParameter,
) -> IdentityFunction:
    """
    Decorator to mark function parameters.

    This decorator expects a number of `RemovedParameter` or `RenamedParameter`
    instances that describe each of the removed parameters of the method.
    """
    assert len(params) == len({p.name for p in params}), (
        "duplicate parameter in removed parameter list"
    )
    params_dict = {p.name: p for p in params}

    def decorate(function: Callable[P, T]) -> Callable[P, T]:
        @wraps(function)

View on GitHub (pinned to 5d8ebabf11)

Solutions

1. Check the spelling against the current API docs (e.g. it's columns not coloumns)
2. Use dir(obj) or getattr(obj, 'name', default) to introspect available attributes
3. Search the migration guide in case the attribute was renamed
4. Update IDE stubs/types so autocomplete matches the installed version

Example fix

# before
df.coloumns
# after
df.columns

valid = [a for a in dir(df) if 'col' in a.lower()]

def has_attr(obj: object, name: str) -> bool:
    return hasattr(obj, name) or name in dir(obj)

try:
    val = getattr(obj, name)
except AttributeError as e:
    raise AttributeError(f'{name} missing on {type(obj).__name__}: check docs') from e

When it happens

Trigger: Accessing any misspelled or nonexistent attribute on polars classes that install getattr_fallback in their metaclass or __getattr__ chain, e.g. df.coloumns, pl.DataFame, Expr.lst.sum.

Common situations: Typos in attribute names, autocomplete suggestions from outdated tutorials, or code written against a different polars version where the attribute never existed or has a different name.

Related errors

• {type(self).__name__!r} object has no attribute {name!r}
• list.to_struct() got a str instead of a list. hint: pass ['{
• schema_mode='overwrite' requires mode='overwrite'
• `{name}` was removed in version {version}
• {func_name!r} received both {param.name!r} and {param.new_na

AI-assisted analysis of pola-rs/polars@5d8ebabf11 (2026-08-28). Data as JSON: /api/errors/ef5f12f3a5d71ff8. Report an issue: GitHub.