def test_dataframe_take(ntake):
np.random.seed(0)
df = DataFrame()
nelem = 123
df["ii"] = np.random.randint(0, 20, nelem)
df["ff"] = np.random.random(nelem)
take_indices = np.random.randint(0, len(df), ntake)
actual = df.take(take_indices)
expected = df.to_pandas().take(take_indices)
assert actual.ii.null_count == 0
assert actual.ff.null_count == 0
assert_eq(actual, expected)
def test_dataframe_take_with_multiIndex(ntake):
np.random.seed(0)
df = DataFrame(index=cudf.MultiIndex(
levels=[["lama", "cow", "falcon"], ["speed", "weight", "length"]],
codes=[[0, 0, 0, 1, 1, 1, 2, 2, 2], [0, 1, 2, 0, 1, 2, 0, 1, 2]],
))
nelem = 9
df["ii"] = np.random.randint(0, 20, nelem)
df["ff"] = np.random.random(nelem)
take_indices = np.random.randint(0, len(df), ntake)
actual = df.take(take_indices)
expected = df.to_pandas().take(take_indices)
assert_eq(actual, expected)
def test_dataframe_take(ntake):
np.random.seed(0)
df = DataFrame()
nelem = 123
df["ii"] = ii = np.random.randint(0, 20, nelem)
df["ff"] = ff = np.random.random(nelem)
take_indices = np.random.randint(0, len(df), ntake)
out = df.take(take_indices)
assert len(out) == ntake
assert out.ii.null_count == 0
assert out.ff.null_count == 0
np.testing.assert_array_equal(out.ii.to_array(), ii[take_indices])
np.testing.assert_array_equal(out.ff.to_array(), ff[take_indices])
np.testing.assert_array_equal(out.index, take_indices)
class MultiIndex(Index):
"""A multi-level or hierarchical index.
Provides N-Dimensional indexing into Series and DataFrame objects.
Properties
---
levels: Labels for each category in the index hierarchy.
codes: Assignment of individual items into the categories of the hierarchy.
names: Name for each level
"""
def __init__(self,
levels=None,
codes=None,
labels=None,
names=None,
**kwargs):
from cudf.core.series import Series
self.name = None
self.names = names
self._source_data = None
column_names = []
if labels:
warnings.warn(
"the 'labels' keyword is deprecated, use 'codes' "
"instead",
FutureWarning,
)
if labels and not codes:
codes = labels
# early termination enables lazy evaluation of codes
if "source_data" in kwargs:
self._source_data = kwargs["source_data"].reset_index(drop=True)
self._codes = codes
self._levels = levels
return
# name setup
if isinstance(
names,
(
Sequence,
pd.core.indexes.frozen.FrozenNDArray,
pd.core.indexes.frozen.FrozenList,
),
):
if sum(x is None for x in names) > 1:
column_names = list(range(len(codes)))
else:
column_names = names
elif names is None:
column_names = list(range(len(codes)))
else:
column_names = names
if len(levels) == 0:
raise ValueError("Must pass non-zero number of levels/codes")
from cudf import DataFrame
if not isinstance(codes, DataFrame) and not isinstance(
codes[0], (Sequence, pd.core.indexes.frozen.FrozenNDArray)):
raise TypeError("Codes is not a Sequence of sequences")
if isinstance(codes, DataFrame):
self._codes = codes
elif len(levels) == len(codes):
self._codes = DataFrame()
for i, codes in enumerate(codes):
name = column_names[i] or i
codes = column.as_column(codes)
self._codes[name] = codes.astype(np.int64)
else:
raise ValueError("MultiIndex has unequal number of levels and "
"codes and is inconsistent!")
self._levels = [Series(level) for level in levels]
self._validate_levels_and_codes(self._levels, self._codes)
self._source_data = DataFrame()
for i, name in enumerate(self._codes.columns):
codes = as_index(self._codes[name]._column)
if -1 in self._codes[name].values:
# Must account for null(s) in _source_data column
level = DataFrame(
{name: [None] + list(self._levels[i])},
index=range(-1, len(self._levels[i])),
)
else:
level = DataFrame({name: self._levels[i]})
level = DataFrame(index=codes).join(level)
self._source_data[name] = level[name].reset_index(drop=True)
self.names = [None] * len(self._levels) if names is None else names
def _validate_levels_and_codes(self, levels, codes):
if len(levels) != len(codes.columns):
raise ValueError("MultiIndex has unequal number of levels and "
"codes and is inconsistent!")
code_length = len(codes[codes.columns[0]])
for index, code in enumerate(codes):
if code_length != len(codes[code]):
raise ValueError("MultiIndex length of codes does not match "
"and is inconsistent!")
for index, code in enumerate(codes):
if codes[code].max() > len(levels[index]) - 1:
raise ValueError("MultiIndex code %d contains value %d larger "
"than maximum level size at this position")
def copy(self, deep=True):
mi = MultiIndex(source_data=self._source_data.copy(deep))
if self._levels is not None:
mi._levels = [s.copy(deep) for s in self._levels]
if self._codes is not None:
mi._codes = self._codes.copy(deep)
if self.names is not None:
mi.names = self.names.copy()
return mi
def deepcopy(self):
return self.copy(deep=True)
def __copy__(self):
return self.copy(deep=True)
def _popn(self, n):
""" Returns a copy of this index without the left-most n values.
Removes n names, labels, and codes in order to build a new index
for results.
"""
from cudf import DataFrame
codes = DataFrame()
for idx in self.codes.columns[n:]:
codes.add_column(idx, self.codes[idx])
result = MultiIndex(self.levels[n:], codes)
if self.names is not None:
result.names = self.names[n:]
return result
def __repr__(self):
return ("MultiIndex(levels=" + str(self.levels) + ",\ncodes=" +
str(self.codes) + ")")
@property
def codes(self):
if self._codes is None:
self._compute_levels_and_codes()
return self._codes
@property
def levels(self):
if self._levels is None:
self._compute_levels_and_codes()
return self._levels
@property
def labels(self):
warnings.warn(
"This feature is deprecated in pandas and will be"
"dropped from cudf as well.",
FutureWarning,
)
return self.codes
def _compute_levels_and_codes(self):
levels = []
from cudf import DataFrame
codes = DataFrame()
for name in self._source_data.columns:
code, cats = self._source_data[name].factorize()
codes[name] = code.reset_index(drop=True).astype(np.int64)
cats.name = None
cats = cats.reset_index(drop=True)._copy_construct(name=None)
levels.append(cats)
self._levels = levels
self._codes = codes
def _compute_validity_mask(self, index, row_tuple, max_length):
""" Computes the valid set of indices of values in the lookup
"""
from cudf import DataFrame
from cudf import Series
from cudf import concat
from cudf.utils.cudautils import arange
lookup = DataFrame()
for idx, row in enumerate(row_tuple):
if row == slice(None):
continue
lookup[index._source_data.columns[idx]] = Series(row)
data_table = concat(
[
index._source_data,
DataFrame({"idx": Series(arange(len(index._source_data)))}),
],
axis=1,
)
result = lookup.merge(data_table)["idx"]
# Avoid computing levels unless the result of the merge is empty,
# which suggests that a KeyError should be raised.
if len(result) == 0:
for idx, row in enumerate(row_tuple):
if row == slice(None):
continue
if row not in index.levels[idx]._column:
raise KeyError(row)
return result
def _get_valid_indices_by_tuple(self, index, row_tuple, max_length):
from cudf.utils.cudautils import arange
from cudf import Series
# Instructions for Slicing
# if tuple, get first and last elements of tuple
# if open beginning tuple, get 0 to highest valid_index
# if open ending tuple, get highest valid_index to len()
# if not open end or beginning, get range lowest beginning index
# to highest ending index
if isinstance(row_tuple, slice):
if (isinstance(row_tuple.start, numbers.Number)
or isinstance(row_tuple.stop, numbers.Number)
or row_tuple == slice(None)):
stop = row_tuple.stop or max_length
start, stop, step = row_tuple.indices(stop)
return arange(start, stop, step)
start_values = self._compute_validity_mask(index, row_tuple.start,
max_length)
stop_values = self._compute_validity_mask(index, row_tuple.stop,
max_length)
return Series(arange(start_values.min(), stop_values.max() + 1))
elif isinstance(row_tuple, numbers.Number):
return row_tuple
return self._compute_validity_mask(index, row_tuple, max_length)
def _index_and_downcast(self, result, index, index_key):
from cudf import DataFrame
from cudf import Series
if isinstance(index_key, (numbers.Number, slice)):
index_key = [index_key]
if (len(index_key) > 0
and not isinstance(index_key, tuple)) or isinstance(
index_key[0], slice):
index_key = index_key[0]
slice_access = False
if isinstance(index_key, slice):
slice_access = True
out_index = DataFrame()
# Select the last n-k columns where n is the number of _source_data
# columns and k is the length of the indexing tuple
size = 0
if not isinstance(index_key, (numbers.Number, slice)):
size = len(index_key)
for k in range(size, len(index._source_data.columns)):
out_index.add_column(
index.names[k],
index._source_data[index._source_data.columns[k]],
)
if len(result) == 1 and size == 0 and slice_access is False:
# If the final result is one row and it was not mapped into
# directly, return a Series with a tuple as name.
result = result.T
result = result[result.columns[0]]
elif len(result) == 0 and slice_access is False:
# Pandas returns an empty Series with a tuple as name
# the one expected result column
series_name = []
for idx, code in enumerate(index._source_data.columns):
series_name.append(index._source_data[code][0])
result = Series([])
result.name = tuple(series_name)
elif len(out_index.columns) == 1:
# If there's only one column remaining in the output index, convert
# it into an Index and name the final index values according
# to the _source_data column names
last_column = index._source_data.columns[-1]
out_index = index._source_data[last_column]
out_index = as_index(out_index)
out_index.name = index.names[len(index.names) - 1]
index = out_index
elif len(out_index.columns) > 1:
# Otherwise pop the leftmost levels, names, and codes from the
# source index until it has the correct number of columns (n-k)
result.reset_index(drop=True)
index = index._popn(size)
if isinstance(index_key, tuple):
result = result.set_index(index)
return result
def _get_row_major(self, df, row_tuple):
from cudf import Series
valid_indices = self._get_valid_indices_by_tuple(
df.index, row_tuple, len(df.index))
indices = Series(valid_indices)
result = df.take(indices)
final = self._index_and_downcast(result, result.index, row_tuple)
return final
def _get_column_major(self, df, row_tuple):
from cudf import Series
from cudf import DataFrame
valid_indices = self._get_valid_indices_by_tuple(
df.columns, row_tuple, len(df._cols))
result = df._take_columns(valid_indices)
if isinstance(row_tuple, (numbers.Number, slice)):
row_tuple = [row_tuple]
if len(result) == 0 and len(result.columns) == 0:
result_columns = df.columns.copy(deep=False)
clear_codes = DataFrame()
for name in df.columns.names:
clear_codes[name] = Series([])
result_columns._codes = clear_codes
result_columns._source_data = clear_codes
result.columns = result_columns
elif len(row_tuple) < len(
self.levels) and (not slice(None) in row_tuple
and not isinstance(row_tuple[0], slice)):
columns = self._popn(len(row_tuple))
result.columns = columns.take(valid_indices)
else:
result.columns = self.take(valid_indices)
if len(result.columns.levels) == 1:
columns = []
for code in result.columns.codes[result.columns.codes.columns[0]]:
columns.append(result.columns.levels[0][code])
name = result.columns.names[0]
result.columns = as_index(columns, name=name)
if len(row_tuple) == len(self.levels) and len(result.columns) == 1:
result = list(result._cols.values())[0]
return result
def _split_tuples(self, tuples):
if len(tuples) == 1:
return tuples, slice(None)
elif isinstance(tuples[0], tuple):
row = tuples[0]
if len(tuples) == 1:
column = slice(None)
else:
column = tuples[1]
return row, column
elif isinstance(tuples[0], slice):
return tuples
else:
return tuples, slice(None)
def __len__(self):
return len(self._source_data)
def equals(self, other):
if self is other:
return True
if len(self) != len(other):
return False
return self == other
def __eq__(self, other):
if not hasattr(other, "_levels"):
return False
# Lazy comparison
if isinstance(other, MultiIndex) or hasattr(other, "_source_data"):
return self._source_data.equals(other._source_data)
else:
# Lazy comparison isn't possible - MI was created manually.
# Actually compare the MI, not its source data (it doesn't have
# any).
equal_levels = self.levels == other.levels
if isinstance(equal_levels, np.ndarray):
equal_levels = equal_levels.all()
return (equal_levels and self.codes.equals(other.codes)
and self.names == other.names)
@property
def is_contiguous(self):
return True
@property
def size(self):
return len(self._source_data)
def take(self, indices):
from collections.abc import Sequence
from cudf import Series
from numbers import Integral
if isinstance(indices, (Integral, Sequence)):
indices = np.array(indices)
elif isinstance(indices, Series):
if indices.null_count != 0:
raise ValueError("Column must have no nulls.")
indices = indices.data.mem
elif isinstance(indices, slice):
start, stop, step = indices.indices(len(self))
indices = cudautils.arange(start, stop, step)
result = MultiIndex(source_data=self._source_data.take(indices))
if self._codes is not None:
result._codes = self._codes.take(indices)
if self._levels is not None:
result._levels = self._levels
result.names = self.names
return result
def serialize(self):
"""Serialize into pickle format suitable for file storage or network
transmission.
"""
header = {}
header["type"] = pickle.dumps(type(self))
header["names"] = pickle.dumps(self.names)
header["source_data"], frames = self._source_data.serialize()
return header, frames
@classmethod
def deserialize(cls, header, frames):
"""Convert from pickle format into Index
"""
names = pickle.loads(header["names"])
source_data_typ = pickle.loads(header["source_data"]["type"])
source_data = source_data_typ.deserialize(header["source_data"],
frames)
names = pickle.loads(header["names"])
return MultiIndex(names=names, source_data=source_data)
def __iter__(self):
self.n = 0
return self
def __next__(self):
if self.n < len(self.codes):
result = self[self.n]
self.n += 1
return result
else:
raise StopIteration
def __getitem__(self, index):
# TODO: This should be a take of the _source_data only
match = self.take(index)
if isinstance(index, slice):
return match
result = []
for level, item in enumerate(match.codes):
result.append(match.levels[level][match.codes[item][0]])
return tuple(result)
def to_frame(self, index=True, name=None):
df = self._source_data
if index:
df = df.set_index(self)
if name:
if len(name) != len(self.levels):
raise ValueError("'name' should have th same length as "
"number of levels on index.")
df.columns = name
return df
def get_level_values(self, level):
colnames = list(self._source_data.columns)
if level not in colnames:
if isinstance(level, int):
if level < 0:
level = level + len(colnames)
if level < 0 or level >= len(colnames):
raise IndexError(f"Invalid level number: '{level}'")
level_idx = level
level = colnames[level_idx]
else:
raise KeyError(f"Level not found: '{level}'")
level_values = self._source_data[level]
return level_values
def _to_frame(self):
from cudf import DataFrame, Series
# for each column of codes
# replace column with mapping from integers to levels
df = self.codes.copy(deep=False)
for idx, col in enumerate(df.columns):
# use merge as a replace fn
level = DataFrame({
"idx":
Series(
cudautils.arange(len(self.levels[idx]),
dtype=df[col].dtype)),
"level":
self.levels[idx],
})
code = DataFrame({"idx": df[col]})
df[col] = code.merge(level).level
return df
@property
def _values(self):
return list([i for i in self])
@classmethod
def _concat(cls, objs):
from cudf import DataFrame, MultiIndex
source_data = [o._source_data for o in objs]
source_data = DataFrame._concat(source_data)
names = [None for x in source_data.columns]
objs = list(filter(lambda o: o.names is not None, objs))
for o in range(len(objs)):
for i, name in enumerate(objs[o].names):
names[i] = names[i] or name
return MultiIndex(names=names, source_data=source_data)
@classmethod
def from_tuples(cls, tuples, names=None):
# Use Pandas for handling Python host objects
pdi = pd.MultiIndex.from_tuples(tuples, names=names)
result = cls.from_pandas(pdi)
return result
@classmethod
def from_frame(cls, dataframe, names=None):
return cls(source_data=dataframe, names=names)
@classmethod
def from_product(cls, arrays, names=None):
# Use Pandas for handling Python host objects
pdi = pd.MultiIndex.from_product(arrays, names=names)
result = cls.from_pandas(pdi)
return result
def to_pandas(self):
pandas_codes = []
for code in self.codes.columns:
pandas_codes.append(self.codes[code].to_array())
# We do two things here to mimic Pandas behavior:
# 1. as_index() on each level, so DatetimeColumn becomes DatetimeIndex
# 2. convert levels to numpy array so empty levels become Float64Index
levels = np.array(
[as_index(level).to_pandas() for level in self.levels])
# Backwards compatibility:
# Construct a dummy MultiIndex and check for the codes attr.
# This indicates that it is pandas >= 0.24
# If no codes attr is present it is pandas <= 0.23
if hasattr(pd.MultiIndex([[]], [[]]), "codes"):
pandas_mi = pd.MultiIndex(levels=levels, codes=pandas_codes)
else:
pandas_mi = pd.MultiIndex(levels=levels, labels=pandas_codes)
if self.names is not None:
pandas_mi.names = self.names
return pandas_mi
@classmethod
def from_pandas(cls, multiindex):
"""
Convert from a Pandas MultiIndex
Raises
------
TypeError for invalid input type.
Examples
--------
>>> import cudf
>>> import pandas as pd
>>> pmi = pd.MultiIndex(levels=[['a', 'b'], ['c', 'd']],
codes=[[0, 1], [1, ]])
>>> cudf.from_pandas(pmi)
MultiIndex( ... )
"""
if not isinstance(multiindex, pd.MultiIndex):
raise TypeError("not a pandas.MultiIndex")
if hasattr(multiindex, "codes"):
mi = cls(
levels=multiindex.levels,
codes=multiindex.codes,
names=multiindex.names,
)
else:
mi = cls(
levels=multiindex.levels,
codes=multiindex.labels,
names=multiindex.names,
)
return mi
@property
def is_unique(self):
if not hasattr(self, "_is_unique"):
self._is_unique = (self._source_data._size ==
self._source_data.drop_duplicates()._size)
return self._is_unique
@property
def is_monotonic_increasing(self):
if not hasattr(self, "_is_monotonic_increasing"):
self._is_monotonic_increasing = libcudf.issorted.issorted(
self._source_data._columns)
return self._is_monotonic_increasing
@property
def is_monotonic_decreasing(self):
if not hasattr(self, "_is_monotonic_decreasing"):
self._is_monotonic_decreasing = libcudf.issorted.issorted(
self._source_data._columns, [1] * len(self.levels))
return self._is_monotonic_decreasing
def repeat(self, repeats, axis=None):
assert axis in (None, 0)
return MultiIndex.from_frame(self._source_data.repeat(repeats),
names=self.names)
class MultiIndex(Index):
"""A multi-level or hierarchical index.
Provides N-Dimensional indexing into Series and DataFrame objects.
Properties
---
levels: Labels for each category in the index hierarchy.
codes: Assignment of individual items into the categories of the hierarchy.
names: Name for each level
"""
def __init__(
self, levels=None, codes=None, labels=None, names=None, **kwargs
):
from cudf.core.series import Series
from cudf import DataFrame
super().__init__()
self._name = None
column_names = []
if labels:
warnings.warn(
"the 'labels' keyword is deprecated, use 'codes' " "instead",
FutureWarning,
)
if labels and not codes:
codes = labels
# early termination enables lazy evaluation of codes
if "source_data" in kwargs:
source_data = kwargs["source_data"].copy(deep=False)
source_data.reset_index(drop=True, inplace=True)
if isinstance(source_data, pd.DataFrame):
nan_as_null = kwargs.get("nan_as_null", None)
source_data = DataFrame.from_pandas(
source_data, nan_as_null=nan_as_null
)
names = names if names is not None else source_data._data.names
# if names are unique
# try using those as the source_data column names:
if len(dict.fromkeys(names)) == len(names):
source_data.columns = names
self._data = source_data._data
self.names = names
self._codes = codes
self._levels = levels
return
# name setup
if isinstance(
names,
(
Sequence,
pd.core.indexes.frozen.FrozenNDArray,
pd.core.indexes.frozen.FrozenList,
),
):
if sum(x is None for x in names) > 1:
column_names = list(range(len(codes)))
else:
column_names = names
elif names is None:
column_names = list(range(len(codes)))
else:
column_names = names
if len(levels) == 0:
raise ValueError("Must pass non-zero number of levels/codes")
if not isinstance(codes, DataFrame) and not isinstance(
codes[0], (Sequence, pd.core.indexes.frozen.FrozenNDArray)
):
raise TypeError("Codes is not a Sequence of sequences")
if isinstance(codes, DataFrame):
self._codes = codes
elif len(levels) == len(codes):
self._codes = DataFrame()
for i, codes in enumerate(codes):
name = column_names[i] or i
codes = column.as_column(codes)
self._codes[name] = codes.astype(np.int64)
else:
raise ValueError(
"MultiIndex has unequal number of levels and "
"codes and is inconsistent!"
)
self._levels = [Series(level) for level in levels]
self._validate_levels_and_codes(self._levels, self._codes)
source_data = DataFrame()
for i, name in enumerate(self._codes.columns):
codes = as_index(self._codes[name]._column)
if -1 in self._codes[name].values:
# Must account for null(s) in _source_data column
level = DataFrame(
{name: [None] + list(self._levels[i])},
index=range(-1, len(self._levels[i])),
)
else:
level = DataFrame({name: self._levels[i]})
import cudf._lib as libcudf
source_data[name] = libcudf.copying.gather(
level, codes._data.columns[0]
)._data[name]
self._data = source_data._data
self.names = names
@property
def names(self):
return self._names
@names.setter
def names(self, value):
value = [None] * self.nlevels if value is None else value
assert len(value) == self.nlevels
self._names = pd.core.indexes.frozen.FrozenList(value)
@classmethod
def _from_table(cls, table, names=None):
df = cudf.DataFrame(table._data)
if names is None:
names = df.columns
return MultiIndex.from_frame(df, names=names)
@property
def _source_data(self):
return cudf.DataFrame(self._data)
@_source_data.setter
def _source_data(self, value):
self._data = value._data
self._compute_levels_and_codes()
@property
def name(self):
return self._name
@name.setter
def name(self, value):
self._name = value
def _validate_levels_and_codes(self, levels, codes):
if len(levels) != len(codes.columns):
raise ValueError(
"MultiIndex has unequal number of levels and "
"codes and is inconsistent!"
)
code_length = len(codes[codes.columns[0]])
for index, code in enumerate(codes):
if code_length != len(codes[code]):
raise ValueError(
"MultiIndex length of codes does not match "
"and is inconsistent!"
)
for index, code in enumerate(codes):
if codes[code].max() > len(levels[index]) - 1:
raise ValueError(
"MultiIndex code %d contains value %d larger "
"than maximum level size at this position"
)
def copy(self, deep=True):
mi = MultiIndex(source_data=self._source_data.copy(deep))
if self._levels is not None:
mi._levels = [s.copy(deep) for s in self._levels]
if self._codes is not None:
mi._codes = self._codes.copy(deep)
if self.names is not None:
mi.names = self.names.copy()
return mi
def deepcopy(self):
return self.copy(deep=True)
def __copy__(self):
return self.copy(deep=True)
def _popn(self, n):
""" Returns a copy of this index without the left-most n values.
Removes n names, labels, and codes in order to build a new index
for results.
"""
result = MultiIndex(source_data=self._source_data.iloc[:, n:])
if self.names is not None:
result.names = self.names[n:]
return result
def __repr__(self):
return (
"MultiIndex(levels="
+ str(self.levels)
+ ",\ncodes="
+ str(self.codes)
+ ")"
)
@property
def codes(self):
if self._codes is None:
self._compute_levels_and_codes()
return self._codes
@property
def nlevels(self):
return self._source_data.shape[1]
@property
def levels(self):
if self._levels is None:
self._compute_levels_and_codes()
return self._levels
@property
def labels(self):
warnings.warn(
"This feature is deprecated in pandas and will be"
"dropped from cudf as well.",
FutureWarning,
)
return self.codes
@property
def ndim(self):
"""Dimension of the data. For MultiIndex ndim is always 2.
"""
return 2
def isin(self, values, level=None):
"""Return a boolean array where the index values are in values.
Compute boolean array of whether each index value is found in
the passed set of values. The length of the returned boolean
array matches the length of the index.
Parameters
----------
values : set, list-like, Index or Multi-Index
Sought values.
level : str or int, optional
Name or position of the index level to use (if the index
is a MultiIndex).
Returns
-------
is_contained : cupy array
CuPy array of boolean values.
Notes
-------
When `level` is None, `values` can only be MultiIndex, or a
set/list-like tuples.
When `level` is provided, `values` can be Index or MultiIndex,
or a set/list-like tuples.
"""
from cudf.utils.dtypes import is_list_like
if level is None:
if isinstance(values, cudf.MultiIndex):
values_idx = values
elif (
(
isinstance(
values,
(
cudf.Series,
cudf.Index,
cudf.DataFrame,
column.ColumnBase,
),
)
)
or (not is_list_like(values))
or (
is_list_like(values)
and len(values) > 0
and not isinstance(values[0], tuple)
)
):
raise TypeError(
"values need to be a Multi-Index or set/list-like tuple \
squences when `level=None`."
)
else:
values_idx = cudf.MultiIndex.from_tuples(
values, names=self.names
)
res = []
for name in self.names:
level_idx = self.get_level_values(name)
value_idx = values_idx.get_level_values(name)
existence = level_idx.isin(value_idx)
res.append(existence)
result = res[0]
for i in res[1:]:
result = result & i
else:
level_series = self.get_level_values(level)
result = level_series.isin(values)
return result
def mask(self, cond, other=None, inplace=False):
raise NotImplementedError(
".mask is not supported for MultiIndex operations"
)
def where(self, cond, other=None, inplace=False):
raise NotImplementedError(
".where is not supported for MultiIndex operations"
)
def _compute_levels_and_codes(self):
levels = []
from cudf import DataFrame
codes = DataFrame()
for name in self._source_data.columns:
code, cats = self._source_data[name].factorize()
codes[name] = code.reset_index(drop=True).astype(np.int64)
cats.name = None
cats = cats.reset_index(drop=True)._copy_construct(name=None)
levels.append(cats)
self._levels = levels
self._codes = codes
def _compute_validity_mask(self, index, row_tuple, max_length):
""" Computes the valid set of indices of values in the lookup
"""
from cudf import DataFrame
from cudf import Series
from cudf import concat
lookup = DataFrame()
for idx, row in enumerate(row_tuple):
if isinstance(row, slice) and row == slice(None):
continue
lookup[index._source_data.columns[idx]] = Series(row)
data_table = concat(
[
index._source_data,
DataFrame(
{"idx": Series(cupy.arange(len(index._source_data)))}
),
],
axis=1,
)
result = lookup.merge(data_table)["idx"]
# Avoid computing levels unless the result of the merge is empty,
# which suggests that a KeyError should be raised.
if len(result) == 0:
for idx, row in enumerate(row_tuple):
if row == slice(None):
continue
if row not in index.levels[idx]._column:
raise KeyError(row)
return result
def _get_valid_indices_by_tuple(self, index, row_tuple, max_length):
from cudf import Series
# Instructions for Slicing
# if tuple, get first and last elements of tuple
# if open beginning tuple, get 0 to highest valid_index
# if open ending tuple, get highest valid_index to len()
# if not open end or beginning, get range lowest beginning index
# to highest ending index
if isinstance(row_tuple, slice):
if (
isinstance(row_tuple.start, numbers.Number)
or isinstance(row_tuple.stop, numbers.Number)
or row_tuple == slice(None)
):
stop = row_tuple.stop or max_length
start, stop, step = row_tuple.indices(stop)
return cupy.arange(start, stop, step)
start_values = self._compute_validity_mask(
index, row_tuple.start, max_length
)
stop_values = self._compute_validity_mask(
index, row_tuple.stop, max_length
)
return Series(
cupy.arange(start_values.min(), stop_values.max() + 1)
)
elif isinstance(row_tuple, numbers.Number):
return row_tuple
return self._compute_validity_mask(index, row_tuple, max_length)
def _index_and_downcast(self, result, index, index_key):
from cudf import DataFrame
from cudf import Series
if isinstance(index_key, (numbers.Number, slice)):
index_key = [index_key]
if (
len(index_key) > 0 and not isinstance(index_key, tuple)
) or isinstance(index_key[0], slice):
index_key = index_key[0]
slice_access = False
if isinstance(index_key, slice):
slice_access = True
out_index = DataFrame()
# Select the last n-k columns where n is the number of _source_data
# columns and k is the length of the indexing tuple
size = 0
if not isinstance(index_key, (numbers.Number, slice)):
size = len(index_key)
for k in range(size, len(index._source_data.columns)):
if index.names is None:
name = k
else:
name = index.names[k]
out_index.insert(
len(out_index.columns),
name,
index._source_data[index._source_data.columns[k]],
)
if len(result) == 1 and size == 0 and slice_access is False:
# If the final result is one row and it was not mapped into
# directly, return a Series with a tuple as name.
result = result.T
result = result[result._data.names[0]]
elif len(result) == 0 and slice_access is False:
# Pandas returns an empty Series with a tuple as name
# the one expected result column
series_name = []
for idx, code in enumerate(index._source_data.columns):
series_name.append(index._source_data[code][0])
result = Series([])
result.name = tuple(series_name)
elif len(out_index.columns) == 1:
# If there's only one column remaining in the output index, convert
# it into an Index and name the final index values according
# to the _source_data column names
last_column = index._source_data.columns[-1]
out_index = index._source_data[last_column]
out_index = as_index(out_index)
out_index.name = index.names[len(index.names) - 1]
index = out_index
elif len(out_index.columns) > 1:
# Otherwise pop the leftmost levels, names, and codes from the
# source index until it has the correct number of columns (n-k)
result.reset_index(drop=True)
index = index._popn(size)
if isinstance(index_key, tuple):
result = result.set_index(index)
return result
def _get_row_major(self, df, row_tuple):
from cudf import Series
if pd.api.types.is_bool_dtype(row_tuple):
return df[row_tuple]
valid_indices = self._get_valid_indices_by_tuple(
df.index, row_tuple, len(df.index)
)
indices = Series(valid_indices)
result = df.take(indices)
final = self._index_and_downcast(result, result.index, row_tuple)
return final
def _split_tuples(self, tuples):
if len(tuples) == 1:
return tuples, slice(None)
elif isinstance(tuples[0], tuple):
row = tuples[0]
if len(tuples) == 1:
column = slice(None)
else:
column = tuples[1]
return row, column
elif isinstance(tuples[0], slice):
return tuples
else:
return tuples, slice(None)
def __len__(self):
return len(next(iter(self._data.columns)))
def equals(self, other):
if self is other:
return True
if len(self) != len(other):
return False
return self == other
def __eq__(self, other):
if not hasattr(other, "_levels"):
return False
# Lazy comparison
if isinstance(other, MultiIndex) or hasattr(other, "_source_data"):
for self_col, other_col in zip(
self._source_data._data.values(),
other._source_data._data.values(),
):
if not self_col.equals(other_col):
return False
return self.names == other.names
else:
# Lazy comparison isn't possible - MI was created manually.
# Actually compare the MI, not its source data (it doesn't have
# any).
equal_levels = self.levels == other.levels
if isinstance(equal_levels, np.ndarray):
equal_levels = equal_levels.all()
return (
equal_levels
and self.codes.equals(other.codes)
and self.names == other.names
)
@property
def is_contiguous(self):
return True
@property
def size(self):
return len(self._source_data)
def take(self, indices):
from collections.abc import Sequence
from cudf import Series
from numbers import Integral
if isinstance(indices, (Integral, Sequence)):
indices = np.array(indices)
elif isinstance(indices, Series):
if indices.has_nulls:
raise ValueError("Column must have no nulls.")
indices = indices
elif isinstance(indices, slice):
start, stop, step = indices.indices(len(self))
indices = cupy.arange(start, stop, step)
result = MultiIndex(source_data=self._source_data.take(indices))
if self._codes is not None:
result._codes = self._codes.take(indices)
if self._levels is not None:
result._levels = self._levels
result.names = self.names
return result
def serialize(self):
"""Serialize into pickle format suitable for file storage or network
transmission.
"""
header = {}
header["type-serialized"] = pickle.dumps(type(self))
header["names"] = pickle.dumps(self.names)
header["source_data"], frames = self._source_data.serialize()
return header, frames
@classmethod
def deserialize(cls, header, frames):
"""Convert from pickle format into Index
"""
names = pickle.loads(header["names"])
source_data_typ = pickle.loads(
header["source_data"]["type-serialized"]
)
source_data = source_data_typ.deserialize(
header["source_data"], frames
)
names = pickle.loads(header["names"])
return MultiIndex(names=names, source_data=source_data)
def __iter__(self):
self.n = 0
return self
def __next__(self):
if self.n < len(self.codes):
result = self[self.n]
self.n += 1
return result
else:
raise StopIteration
def __getitem__(self, index):
# TODO: This should be a take of the _source_data only
match = self.take(index)
if isinstance(index, slice):
return match
result = []
for level, item in enumerate(match.codes):
result.append(match.levels[level][match.codes[item].iloc[0]])
return tuple(result)
def to_frame(self, index=True, name=None):
df = self._source_data
if index:
df = df.set_index(self)
if name is not None:
if len(name) != len(self.levels):
raise ValueError(
"'name' should have th same length as "
"number of levels on index."
)
df.columns = name
return df
def get_level_values(self, level):
"""
Return the values at the requested level
Parameters
----------
level : int or label
Returns
-------
An Index containing the values at the requested level.
"""
colnames = list(self._source_data.columns)
if level not in colnames:
if isinstance(level, int):
if level < 0:
level = level + len(colnames)
if level < 0 or level >= len(colnames):
raise IndexError(f"Invalid level number: '{level}'")
level_idx = level
level = colnames[level_idx]
elif level in self.names:
level_idx = list(self.names).index(level)
level = colnames[level_idx]
else:
raise KeyError(f"Level not found: '{level}'")
else:
level_idx = colnames.index(level)
level_values = as_index(
self._source_data._data[level], name=self.names[level_idx]
)
return level_values
def _to_frame(self):
from cudf import DataFrame, Series
# for each column of codes
# replace column with mapping from integers to levels
df = self.codes.copy(deep=False)
for idx, col in enumerate(df.columns):
# use merge as a replace fn
level = DataFrame(
{
"idx": Series(
cupy.arange(len(self.levels[idx]), dtype=df[col].dtype)
),
"level": self.levels[idx],
}
)
code = DataFrame({"idx": df[col]})
df[col] = code.merge(level).level
return df
@property
def _values(self):
return list([i for i in self])
@classmethod
def _concat(cls, objs):
from cudf import DataFrame, MultiIndex
source_data = [o._source_data for o in objs]
source_data = DataFrame._concat(source_data)
names = [None for x in source_data.columns]
objs = list(filter(lambda o: o.names is not None, objs))
for o in range(len(objs)):
for i, name in enumerate(objs[o].names):
names[i] = names[i] or name
return MultiIndex(names=names, source_data=source_data)
@classmethod
def from_tuples(cls, tuples, names=None):
# Use Pandas for handling Python host objects
pdi = pd.MultiIndex.from_tuples(tuples, names=names)
result = cls.from_pandas(pdi)
return result
@classmethod
def from_frame(cls, dataframe, names=None):
return cls(source_data=dataframe, names=names)
@classmethod
def from_product(cls, arrays, names=None):
# Use Pandas for handling Python host objects
pdi = pd.MultiIndex.from_product(arrays, names=names)
result = cls.from_pandas(pdi)
return result
def to_pandas(self):
if hasattr(self, "_source_data"):
result = self._source_data.to_pandas()
result.columns = self.names
return pd.MultiIndex.from_frame(result)
pandas_codes = []
for code in self.codes.columns:
pandas_codes.append(self.codes[code].to_array())
# We do two things here to mimic Pandas behavior:
# 1. as_index() on each level, so DatetimeColumn becomes DatetimeIndex
# 2. convert levels to numpy array so empty levels become Float64Index
levels = np.array(
[as_index(level).to_pandas() for level in self.levels]
)
# Backwards compatibility:
# Construct a dummy MultiIndex and check for the codes attr.
# This indicates that it is pandas >= 0.24
# If no codes attr is present it is pandas <= 0.23
if hasattr(pd.MultiIndex([[]], [[]]), "codes"):
pandas_mi = pd.MultiIndex(levels=levels, codes=pandas_codes)
else:
pandas_mi = pd.MultiIndex(levels=levels, labels=pandas_codes)
if self.names is not None:
pandas_mi.names = self.names
return pandas_mi
@classmethod
def from_pandas(cls, multiindex, nan_as_null=None):
"""
Convert from a Pandas MultiIndex
Raises
------
TypeError for invalid input type.
Examples
--------
>>> import cudf
>>> import pandas as pd
>>> pmi = pd.MultiIndex(levels=[['a', 'b'], ['c', 'd']],
codes=[[0, 1], [1, ]])
>>> cudf.from_pandas(pmi)
MultiIndex( ... )
"""
if not isinstance(multiindex, pd.MultiIndex):
raise TypeError("not a pandas.MultiIndex")
mi = cls(
names=multiindex.names,
source_data=multiindex.to_frame(),
nan_as_null=nan_as_null,
)
return mi
@property
def is_unique(self):
if not hasattr(self, "_is_unique"):
self._is_unique = len(self._source_data) == len(
self._source_data.drop_duplicates(ignore_index=True)
)
return self._is_unique
@property
def is_monotonic_increasing(self):
if not hasattr(self, "_is_monotonic_increasing"):
self._is_monotonic_increasing = self._is_sorted(
ascending=None, null_position=None
)
return self._is_monotonic_increasing
@property
def is_monotonic_decreasing(self):
if not hasattr(self, "_is_monotonic_decreasing"):
self._is_monotonic_decreasing = self._is_sorted(
ascending=[False] * len(self.levels), null_position=None
)
return self._is_monotonic_decreasing
def argsort(self, ascending=True):
return self._source_data.argsort(ascending=ascending)
def unique(self):
return MultiIndex.from_frame(self._source_data.drop_duplicates())
def memory_usage(self, deep=False):
n = 0
for col in self._source_data._columns:
n += col._memory_usage(deep=deep)
if self._levels:
for level in self._levels:
n += level.memory_usage(deep=deep)
if self._codes:
for col in self._codes._columns:
n += col._memory_usage(deep=deep)
return n
def difference(self, other, sort=None):
temp_self = self
temp_other = other
if hasattr(self, "to_pandas"):
temp_self = self.to_pandas()
if hasattr(other, "to_pandas"):
temp_other = self.to_pandas()
return temp_self.difference(temp_other, sort)
def nan_to_num(*args, **kwargs):
return args[0]
def array_equal(*args, **kwargs):
return args[0] == args[1]
def __array_function__(self, func, types, args, kwargs):
cudf_df_module = MultiIndex
for submodule in func.__module__.split(".")[1:]:
# point cudf to the correct submodule
if hasattr(cudf_df_module, submodule):
cudf_df_module = getattr(cudf_df_module, submodule)
else:
return NotImplemented
fname = func.__name__
handled_types = [cudf_df_module, np.ndarray]
for t in types:
if t not in handled_types:
return NotImplemented
if hasattr(cudf_df_module, fname):
cudf_func = getattr(cudf_df_module, fname)
# Handle case if cudf_func is same as numpy function
if cudf_func is func:
return NotImplemented
else:
return cudf_func(*args, **kwargs)
else:
return NotImplemented
def _mimic_inplace(self, other, inplace=False):
if inplace is True:
for in_col, oth_col in zip(
self._source_data._columns, other._source_data._columns,
):
in_col._mimic_inplace(oth_col, inplace=True)
else:
return other
