pytest-dev/pytest · error · TypeError

must be absolute import path string, not

Error message

must be absolute import path string, not {import_path!r}

What it means

A TypeError raised by derive_importpath when the import_path argument is not a string or does not contain a dot. pytest requires a dotted absolute import path (at least module.attribute) so it can split on the last dot into module and attribute. Non-strings (objects, None) and dot-less strings are rejected upfront.

Solutions

1. Provide a fully qualified dotted path including the attribute: 'module.Class.attribute'.
2. If you have the object already, use the three-arg form: setattr(target_obj, 'name', value).
3. Ensure the path string contains at least one dot separating module from attribute.

Example fix

# before
monkeypatch.setattr('ospath', new)
# after
monkeypatch.setattr('os.path', new)

def is_dotted_path(p) -> bool:
    return isinstance(p, str) and '.' in p

def is_dotted_import_path(p) -> bool:
    return isinstance(p, str) and '.' in p

When it happens

Trigger: Calling `monkeypatch.setattr(123, value)`, `monkeypatch.setattr('nomodule', value)` (no dot), `monkeypatch.setattr(None, value)`, or `monkeypatch.delattr('justaname')`. The check `not isinstance(import_path, str) or '.' not in import_path` catches both cases.

Common situations: Confusing the two-arg and three-arg setattr forms; passing a module object where a dotted string is expected; forgetting the attribute portion when only a module name is given.

Related errors

• import error in
• object at has no attribute
• use setattr(target, name, value) or setattr(target, value)…
• use setattr(target, name, value) with name being a string…
• `allow_unwrapped=True` bypasses the `match` and `check`…

AI-assisted analysis of pytest-dev/pytest@0d6fbdeffa (2026-08-11). Data as JSON: /api/errors/9465c8efbc5fa489. Report an issue: GitHub.

Appendix: source

Thrown at src/_pytest/monkeypatch.py:105

            else:
                raise ImportError(f"import error in {used}: {ex}") from ex
        found = annotated_getattr(found, part, used)
    return found


def annotated_getattr(obj: object, name: str, ann: str) -> object:
    try:
        obj = getattr(obj, name)
    except AttributeError as e:
        raise AttributeError(
            f"{type(obj).__name__!r} object at {ann} has no attribute {name!r}"
        ) from e
    return obj


def derive_importpath(import_path: str, raising: bool) -> tuple[str, object]:
    if not isinstance(import_path, str) or "." not in import_path:
        raise TypeError(f"must be absolute import path string, not {import_path!r}")
    module, attr = import_path.rsplit(".", 1)
    target = resolve(module)
    if raising:
        annotated_getattr(target, attr, ann=module)
    return attr, target


@final
class MonkeyPatch:
    """Helper to conveniently monkeypatch attributes/items/environment
    variables/syspath.

    Returned by the :fixture:`monkeypatch` fixture.

    .. versionchanged:: 6.2
        Can now also be used directly as `pytest.MonkeyPatch()`, for when
        the fixture is not available. In this case, use
        :meth:`with MonkeyPatch.context() as mp: <context>` or remember to call

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