def get_mgr_concatenation_plan(mgr, indexers):
"""
Construct concatenation plan for given block manager and indexers.
Parameters
----------
mgr : BlockManager
indexers : dict of {axis: indexer}
Returns
-------
plan : list of (BlockPlacement, JoinUnit) tuples
"""
# Calculate post-reindex shape , save for item axis which will be separate
# for each block anyway.
mgr_shape = list(mgr.shape)
for ax, indexer in indexers.items():
mgr_shape[ax] = len(indexer)
mgr_shape = tuple(mgr_shape)
if 0 in indexers:
ax0_indexer = indexers.pop(0)
blknos = algos.take_1d(mgr._blknos, ax0_indexer, fill_value=-1)
blklocs = algos.take_1d(mgr._blklocs, ax0_indexer, fill_value=-1)
else:
if mgr._is_single_block:
blk = mgr.blocks[0]
return [(blk.mgr_locs, JoinUnit(blk, mgr_shape, indexers))]
ax0_indexer = None
blknos = mgr._blknos
blklocs = mgr._blklocs
plan = []
for blkno, placements in libinternals.get_blkno_placements(blknos,
mgr.nblocks,
group=False):
assert placements.is_slice_like
join_unit_indexers = indexers.copy()
shape = list(mgr_shape)
shape[0] = len(placements)
shape = tuple(shape)
if blkno == -1:
unit = JoinUnit(None, shape)
else:
blk = mgr.blocks[blkno]
ax0_blk_indexer = blklocs[placements.indexer]
unit_no_ax0_reindexing = (len(placements) == len(blk.mgr_locs) and
# Fastpath detection of join unit not
# needing to reindex its block: no ax0
# reindexing took place and block
# placement was sequential before.
((ax0_indexer is None and
blk.mgr_locs.is_slice_like and
blk.mgr_locs.as_slice.step == 1) or
# Slow-ish detection: all indexer locs
# are sequential (and length match is
# checked above).
(np.diff(ax0_blk_indexer) == 1).all()))
# Omit indexer if no item reindexing is required.
if unit_no_ax0_reindexing:
join_unit_indexers.pop(0, None)
else:
join_unit_indexers[0] = ax0_blk_indexer
unit = JoinUnit(blk, shape, join_unit_indexers)
plan.append((placements, unit))
return plan
def get_mgr_concatenation_plan(mgr, indexers):
"""
Construct concatenation plan for given block manager and indexers.
Parameters
----------
mgr : BlockManager
indexers : dict of {axis: indexer}
Returns
-------
plan : list of (BlockPlacement, JoinUnit) tuples
"""
# Calculate post-reindex shape , save for item axis which will be separate
# for each block anyway.
mgr_shape = list(mgr.shape)
for ax, indexer in indexers.items():
mgr_shape[ax] = len(indexer)
mgr_shape = tuple(mgr_shape)
if 0 in indexers:
ax0_indexer = indexers.pop(0)
blknos = algos.take_1d(mgr._blknos, ax0_indexer, fill_value=-1)
blklocs = algos.take_1d(mgr._blklocs, ax0_indexer, fill_value=-1)
else:
if mgr._is_single_block:
blk = mgr.blocks[0]
return [(blk.mgr_locs, JoinUnit(blk, mgr_shape, indexers))]
ax0_indexer = None
blknos = mgr._blknos
blklocs = mgr._blklocs
plan = []
for blkno, placements in libinternals.get_blkno_placements(blknos,
mgr.nblocks,
group=False):
assert placements.is_slice_like
join_unit_indexers = indexers.copy()
shape = list(mgr_shape)
shape[0] = len(placements)
shape = tuple(shape)
if blkno == -1:
unit = JoinUnit(None, shape)
else:
blk = mgr.blocks[blkno]
ax0_blk_indexer = blklocs[placements.indexer]
unit_no_ax0_reindexing = (len(placements) == len(blk.mgr_locs) and
# Fastpath detection of join unit not
# needing to reindex its block: no ax0
# reindexing took place and block
# placement was sequential before.
((ax0_indexer is None and
blk.mgr_locs.is_slice_like and
blk.mgr_locs.as_slice.step == 1) or
# Slow-ish detection: all indexer locs
# are sequential (and length match is
# checked above).
(np.diff(ax0_blk_indexer) == 1).all()))
# Omit indexer if no item reindexing is required.
if unit_no_ax0_reindexing:
join_unit_indexers.pop(0, None)
else:
join_unit_indexers[0] = ax0_blk_indexer
unit = JoinUnit(blk, shape, join_unit_indexers)
plan.append((placements, unit))
return plan
def _get_mgr_concatenation_plan(mgr: BlockManager):
"""
Construct concatenation plan for given block manager.
Parameters
----------
mgr : BlockManager
Returns
-------
plan : list of (BlockPlacement, JoinUnit) tuples
"""
# Calculate post-reindex shape , save for item axis which will be separate
# for each block anyway.
mgr_shape_list = list(mgr.shape)
mgr_shape = tuple(mgr_shape_list)
if mgr.is_single_block:
blk = mgr.blocks[0]
return [(blk.mgr_locs, JoinUnit(blk, mgr_shape))]
blknos = mgr.blknos
blklocs = mgr.blklocs
plan = []
for blkno, placements in libinternals.get_blkno_placements(blknos,
group=False):
assert placements.is_slice_like
assert blkno != -1
shape_list = list(mgr_shape)
shape_list[0] = len(placements)
shape = tuple(shape_list)
blk = mgr.blocks[blkno]
ax0_blk_indexer = blklocs[placements.indexer]
unit_no_ax0_reindexing = (
len(placements) == len(blk.mgr_locs) and
# Fastpath detection of join unit not
# needing to reindex its block: no ax0
# reindexing took place and block
# placement was sequential before.
((blk.mgr_locs.is_slice_like and blk.mgr_locs.as_slice.step == 1)
or
# Slow-ish detection: all indexer locs
# are sequential (and length match is
# checked above).
(np.diff(ax0_blk_indexer) == 1).all()))
if not unit_no_ax0_reindexing:
# create block from subset of columns
# Note: Blocks with only 1 column will always have unit_no_ax0_reindexing,
# so we will never get here with ExtensionBlock.
blk = blk.getitem_block(ax0_blk_indexer)
# Assertions disabled for performance
# assert blk._mgr_locs.as_slice == placements.as_slice
# assert blk.shape[0] == shape[0]
unit = JoinUnit(blk, shape)
plan.append((placements, unit))
return plan