markowitz.data_providers.factory

markowitz.data_providers.factory

Factory that picks the right provider based on environment configuration.

:func:make_provider returns :class:PolygonProvider when a Polygon API key is available (either passed in or read from POLYGON_API_KEY), and the :class:YFinanceProvider adapter otherwise. The factory is the single recommended entry point for callers that want to be agnostic about whether a key is configured — the Streamlit demo and the universe builder both go through it.

make_provider(api_key: str | None = None, *, inner_yfinance: Any = None) -> PolygonProvider | YFinanceProvider

Return a Polygon provider if a key is configured, otherwise yfinance.

Parameters:

Name	Type	Description	Default
api_key	str | None	Explicit Polygon API key. When None the factory falls back to the POLYGON_API_KEY environment variable.	None
inner_yfinance	Any	Optional pre-built provider passed straight through to :class:YFinanceProvider when the fallback path is taken — useful for tests that need to inject a stub instead of touching the network.	None

Source code in src/markowitz/data_providers/factory.py

def make_provider(
    api_key: str | None = None,
    *,
    inner_yfinance: Any = None,
) -> PolygonProvider | YFinanceProvider:
    """Return a Polygon provider if a key is configured, otherwise yfinance.

    Parameters
    ----------
    api_key:
        Explicit Polygon API key. When ``None`` the factory falls back to the
        ``POLYGON_API_KEY`` environment variable.
    inner_yfinance:
        Optional pre-built provider passed straight through to
        :class:`YFinanceProvider` when the fallback path is taken — useful
        for tests that need to inject a stub instead of touching the network.
    """
    key = (api_key or os.environ.get("POLYGON_API_KEY", "")).strip()
    if key:
        try:
            return PolygonProvider(api_key=key)
        except PolygonAuthError:
            # Construction failed despite a non-empty key — fall back rather
            # than propagate, so the demo keeps running with yfinance data.
            logger.warning(
                "POLYGON_API_KEY present but PolygonProvider rejected it; "
                "falling back to yfinance"
            )
    else:
        logger.info(
            "POLYGON_API_KEY not set; using yfinance provider (no PIT universe)"
        )
    return YFinanceProvider(inner=inner_yfinance)