Source code for mars.contrib.dask.converter

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from dask import is_dask_collection, optimize
from dask.bag import Bag

from ...remote import spawn
from .scheduler import mars_dask_get
from .utils import reduce


[docs]def convert_dask_collection(dc): """ Convert dask collection object into mars.core.Object via remote API Parameters ---------- dc: dask collection Dask collection object to be converted. Returns ------- Object Mars Object. """ if not is_dask_collection(dc): raise TypeError(f"'{type(dc).__name__}' object is not a valid dask collection") dc.__dask_graph__().validate() dsk = optimize(dc)[0].__dask_graph__() first_key = next(iter(dsk.keys())) if isinstance(first_key, str): key = [first_key] elif isinstance(first_key, tuple): key = sorted( [i for i in dsk.keys() if i[0] == first_key[0]], key=lambda x: x[1] ) else: raise ValueError( f"Dask collection object seems be broken, with unexpected key type:'{type(first_key).__name__}'" ) res = reduce(mars_dask_get(dsk, [key])) if isinstance(dc, Bag): return spawn(lambda x: list(x[0][0]), args=(res,)) else: return res