def _concat(cls, objs, dtype=None):
from cudf.dataframe.string import StringColumn
from cudf.dataframe.categorical import CategoricalColumn
if len(objs) == 0:
if pd.api.types.is_categorical_dtype(dtype):
return CategoricalColumn(data=Column(
Buffer.null(np.dtype('int8'))),
null_count=0,
ordered=False)
elif dtype == np.dtype('object'):
return StringColumn(data=nvstrings.to_device([]), null_count=0)
else:
dtype = np.dtype(dtype)
return Column(Buffer.null(dtype))
# Handle strings separately
if all(isinstance(o, StringColumn) for o in objs):
objs = [o._data for o in objs]
return StringColumn(data=nvstrings.from_strings(*objs))
# Handle categories for categoricals
if all(isinstance(o, CategoricalColumn) for o in objs):
new_cats = tuple(set([val for o in objs for val in o]))
objs = [o.cat()._set_categories(new_cats) for o in objs]
head = objs[0]
for o in objs:
if not o.is_type_equivalent(head):
raise ValueError("All series must be of same type")
# Filter out inputs that have 0 length
objs = [o for o in objs if len(o) > 0]
nulls = sum(o.null_count for o in objs)
newsize = sum(map(len, objs))
mem = rmm.device_array(shape=newsize, dtype=head.data.dtype)
data = Buffer.from_empty(mem, size=newsize)
# Allocate output mask only if there's nulls in the input objects
mask = None
if nulls:
mask = Buffer(utils.make_mask(newsize))
col = head.replace(data=data, mask=mask, null_count=nulls)
# Performance the actual concatenation
if newsize > 0:
col = _gdf._column_concat(objs, col)
return col
def _sortjoin(self, other, how='left', return_indexers=False):
"""Join with another column.
When the column is a index, set *return_indexers* to obtain
the indices for shuffling the remaining columns.
"""
from cudf.dataframe.series import Series
if not self.is_type_equivalent(other):
raise TypeError('*other* is not compatible')
lkey, largsort = self.sort_by_values(True)
rkey, rargsort = other.sort_by_values(True)
with _gdf.apply_join(
[lkey], [rkey], how=how, method='sort') as (lidx, ridx):
if lidx.size > 0:
raw_index = cudautils.gather_joined_index(
lkey.to_gpu_array(),
rkey.to_gpu_array(),
lidx,
ridx,
)
buf_index = Buffer(raw_index)
else:
buf_index = Buffer.null(dtype=self.dtype)
joined_index = lkey.replace(data=buf_index)
if return_indexers:
def gather(idxrange, idx):
mask = (Series(idx) != -1).as_mask()
return idxrange.take(idx).set_mask(mask).fillna(-1)
if len(joined_index) > 0:
indexers = (
gather(Series(largsort), lidx),
gather(Series(rargsort), ridx),
)
else:
indexers = (
Series(Buffer.null(dtype=np.intp)),
Series(Buffer.null(dtype=np.intp))
)
return joined_index, indexers
else:
return joined_index
def _hashjoin(self, other, how='left', return_indexers=False):
from cudf.dataframe.series import Series
if not self.is_type_equivalent(other):
raise TypeError('*other* is not compatible')
with _gdf.apply_join(
[self], [other], how=how, method='hash') as (lidx, ridx):
if lidx.size > 0:
raw_index = cudautils.gather_joined_index(
self.to_gpu_array(),
other.to_gpu_array(),
lidx,
ridx,
)
buf_index = Buffer(raw_index)
else:
buf_index = Buffer.null(dtype=self.dtype)
joined_index = self.replace(data=buf_index)
if return_indexers:
def gather(idxrange, idx):
mask = (Series(idx) != -1).as_mask()
return idxrange.take(idx).set_mask(mask).fillna(-1)
if len(joined_index) > 0:
indexers = (
gather(Series(range(0, len(self))), lidx),
gather(Series(range(0, len(other))), ridx),
)
else:
indexers = (
Series(Buffer.null(dtype=np.intp)),
Series(Buffer.null(dtype=np.intp))
)
return joined_index, indexers
else:
return joined_index
def _concat(cls, objs, dtype=None):
from cudf.dataframe.series import Series
from cudf.dataframe.string import StringColumn
from cudf.dataframe.categorical import CategoricalColumn
from cudf.dataframe.numerical import NumericalColumn
if len(objs) == 0:
dtype = pd.api.types.pandas_dtype(dtype)
if dtype.type in (np.object_, np.str_):
return StringColumn(data=nvstrings.to_device([]), null_count=0)
elif is_categorical_dtype(dtype):
return CategoricalColumn(
data=Column(Buffer.null(np.dtype("int8"))),
null_count=0,
ordered=False,
)
else:
return Column(Buffer.null(dtype))
# If all columns are `NumericalColumn` with different dtypes,
# we cast them to a common dtype.
# Notice, we can always cast pure null columns
not_null_cols = list(filter(lambda o: len(o) != o.null_count, objs))
if len(not_null_cols) > 0 and (len([
o for o in not_null_cols if not isinstance(o, NumericalColumn)
or np.issubdtype(o.dtype, np.datetime64)
]) == 0):
col_dtypes = [o.dtype for o in not_null_cols]
# Use NumPy to find a common dtype
common_dtype = np.find_common_type(col_dtypes, [])
# Cast all columns to the common dtype
for i in range(len(objs)):
objs[i] = objs[i].astype(common_dtype)
# Find the first non-null column:
head = objs[0]
for i, obj in enumerate(objs):
if len(obj) != obj.null_count:
head = obj
break
for i, obj in enumerate(objs):
# Check that all columns are the same type:
if not objs[i].is_type_equivalent(head):
# if all null, cast to appropriate dtype
if len(obj) == obj.null_count:
from cudf.dataframe.columnops import column_empty_like
objs[i] = column_empty_like(head,
dtype=head.dtype,
masked=True,
newsize=len(obj))
# Handle categories for categoricals
if all(isinstance(o, CategoricalColumn) for o in objs):
cats = (Series(Column._concat([o.categories for o in objs
])).drop_duplicates()._column)
objs = [
o.cat()._set_categories(cats, is_unique=True) for o in objs
]
head = objs[0]
for obj in objs:
if not (obj.is_type_equivalent(head)):
raise ValueError("All series must be of same type")
# Handle strings separately
if all(isinstance(o, StringColumn) for o in objs):
objs = [o._data for o in objs]
return StringColumn(data=nvstrings.from_strings(*objs))
# Filter out inputs that have 0 length
objs = [o for o in objs if len(o) > 0]
nulls = sum(o.null_count for o in objs)
newsize = sum(map(len, objs))
mem = rmm.device_array(shape=newsize, dtype=head.data.dtype)
data = Buffer.from_empty(mem, size=newsize)
# Allocate output mask only if there's nulls in the input objects
mask = None
if nulls:
mask = Buffer(utils.make_mask(newsize))
col = head.replace(data=data, mask=mask, null_count=nulls)
# Performance the actual concatenation
if newsize > 0:
col = _column_concat(objs, col)
return col