core.py 文件源码

def concat(objs):
    """Concantenate dask gdf objects

    Parameters
    ----------

    objs : sequence of DataFrame, Series, Index
        A sequence of objects to be concatenated.
    """
    objs = [_daskify(x) for x in objs]
    meta = gd.concat(_extract_meta(objs))

    name = "concat-" + uuid4().hex
    dsk = {}
    divisions = [0]
    base = 0
    lastdiv = 0
    for obj in objs:
        for k, i in obj._keys():
            dsk[name, base + i] = k, i
        base += obj.npartitions
        divisions.extend([d + lastdiv for d in obj.divisions[1:]])
        lastdiv = obj.divisions[-1]

    dasks = [o.dask for o in objs]
    dsk = merge(dsk, *dasks)
    return new_dd_object(dsk, name, meta, divisions)