Method __dask_graph__

dask/_expr.py:1392–1419

(self)

            return self.expr

    def __dask_graph__(self):
        try:
            from distributed.shuffle._core import P2PBarrierTask
        except ModuleNotFoundError:
            P2PBarrierTask = type(None)
        dsk = convert_legacy_graph(self.expr.__dask_graph__())

        subs = {old_key: self._modify_keys(old_key) for old_key in dsk}
        dsk2 = {}
        for old_key, new_key in subs.items():
            t = dsk[old_key]
            if isinstance(t, P2PBarrierTask):
                warnings.warn(
                    "Cannot block reusing for graphs including a "
                    "P2PBarrierTask. This may cause unexpected results. "
                    "This typically happens when converting a dask "
                    "DataFrame to delayed objects.",
                    UserWarning,
                )
                return dsk
            dsk2[new_key] = Task(
                new_key,
                ProhibitReuse._identity,
                t.substitute(subs),
            )

        dsk2.update(dsk)
        return dsk2

    _layer = __dask_graph__