nautechsystems/nautilus_trader · error · AttributeError

module {__name__!r} has no attribute {name!r}

Error message

module {__name__!r} has no attribute {name!r}

What it means

Module-level __getattr__ in the testkit providers lazily re-exports only the four pandas-dependent loaders (CSVBarDataLoader, CSVTickDataLoader, ParquetBarDataLoader, ParquetTickDataLoader); any other unresolved attribute name falls through to this standard AttributeError sentinel.

Source

Thrown at python/nautilus_trader/testkit/providers.py:93

    "https://raw.githubusercontent.com/nautechsystems/nautilus_trader/{branch}/test_data/{path}"
)
_DEFAULT_BRANCH = "develop"


def __getattr__(name: str) -> Any:
    # Lazily re-export the data loaders (which require pandas) so that the
    # instrument factories remain importable without pandas installed
    if name in (
        "CSVBarDataLoader",
        "CSVTickDataLoader",
        "ParquetBarDataLoader",
        "ParquetTickDataLoader",
    ):
        from nautilus_trader.persistence import loaders

        return getattr(loaders, name)

    raise AttributeError(f"module {__name__!r} has no attribute {name!r}")


def _read_test_data(path: str, branch: str = _DEFAULT_BRANCH) -> bytes:
    if TEST_DATA_DIR.exists():
        return (TEST_DATA_DIR / path).read_bytes()

    url = _GITHUB_RAW_URL.format(branch=branch, path=path)
    with urllib.request.urlopen(url) as response:  # noqa: S310  # Fixed https scheme
        return response.read()


def _open_test_data_text(path: str) -> io.StringIO:
    return io.StringIO(_read_test_data(path).decode("utf-8"))


def _parse_iso_to_ns(value: str) -> int:
    s = value.strip()
    if "+" not in s and not s.endswith("Z"):

View on GitHub (pinned to 18893faf8b)

Solutions

1. Check the attribute spelling against the testkit module contents
2. Import the data loaders directly from nautilus_trader.persistence.loaders

When it happens

Trigger: Thrown at python/nautilus_trader/testkit/providers.py:93 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of nautechsystems/nautilus_trader@18893faf8b (2026-09-08). Data as JSON: /api/errors/523339c62905cc98. Report an issue: GitHub.