Function _derived_from

dask/utils.py:896–958

Helper function for derived_from to ease testing

(
    cls, method, ua_args=None, extra="", skipblocks=0, inconsistencies=None
)

def _derived_from(
    cls, method, ua_args=None, extra="", skipblocks=0, inconsistencies=None
):
    """Helper function for derived_from to ease testing"""
    ua_args = ua_args or []

    # do not use wraps here, as it hides keyword arguments displayed
    # in the doc
    original_method = getattr(cls, method.__name__)

    doc = getattr(original_method, "__doc__", None)

    if isinstance(original_method, property):
        # some things like SeriesGroupBy.unique are generated.
        original_method = original_method.fget
        if not doc:
            doc = getattr(original_method, "__doc__", None)

    if isinstance(original_method, functools.cached_property):
        original_method = original_method.func
        if not doc:
            doc = getattr(original_method, "__doc__", None)

    if doc is None:
        doc = ""

    # pandas DataFrame/Series sometimes override methods without setting __doc__
    if not doc and cls.__name__ in {"DataFrame", "Series"}:
        for obj in cls.mro():
            obj_method = getattr(obj, method.__name__, None)
            if obj_method is not None and obj_method.__doc__:
                doc = obj_method.__doc__
                break

    # Insert disclaimer that this is a copied docstring
    if doc:
        doc = ignore_warning(
            doc,
            cls,
            method.__name__,
            extra=extra,
            skipblocks=skipblocks,
            inconsistencies=inconsistencies,
        )
    elif extra:
        doc += extra.rstrip("\n") + "\n\n"

    # Mark unsupported arguments
    try:
        method_args = get_named_args(method)
        original_args = get_named_args(original_method)
        not_supported = [m for m in original_args if m not in method_args]
    except ValueError:
        not_supported = []
    if len(ua_args) > 0:
        not_supported.extend(ua_args)
    if len(not_supported) > 0:
        doc = unsupported_arguments(doc, not_supported)