ak.contents.BitMaskedArray#
Defined in awkward.contents.bitmaskedarray on line 52.
- class ak.contents.BitMaskedArray(self, mask, content, valid_when, length, lsb_order, *, parameters=None)#
Like ak.contents.ByteMaskedArray, BitMaskedArray implements an
ak.types.OptionType with two buffers, mask and content.
However, the boolean mask values are packed into a bitmap.
BitMaskedArray has an additional parameter, lsb_order; if True,
the position of each bit is in
Least-Significant Bit order
(LSB):
is_valid[j] = bool(mask[j // 8] & (1 << (j % 8))) == valid_when
If False, the position of each bit is in Most-Significant Bit order (MSB):
is_valid[j] = bool(mask[j // 8] & (128 >> (j % 8))) == valid_when
If the logical size of the buffer is not a multiple of 8, the mask
has to be padded. Thus, an explicit length is also part of the
class’s definition.
This is equivalent to all of Apache Arrow’s array types because they all
use bitmaps
to mask their data, with valid_when=True and lsb_order=True.
To illustrate how the constructor arguments are interpreted, the following is a
simplified implementation of __init__, __len__, and __getitem__:
class BitMaskedArray(Content):
def __init__(self, mask, content, valid_when, length, lsb_order):
assert isinstance(mask, IndexU8)
assert isinstance(content, Content)
assert isinstance(valid_when, bool)
assert isinstance(length, int) and length >= 0
assert isinstance(lsb_order, bool)
assert len(mask) <= len(content)
self.mask = mask
self.content = content
self.valid_when = valid_when
self.length = length
self.lsb_order = lsb_order
def __len__(self):
return self.length
def __getitem__(self, where):
if isinstance(where, int):
if where < 0:
where += len(self)
assert 0 <= where < len(self)
if self.lsb_order:
bit = bool(self.mask[where // 8] & (1 << (where % 8)))
else:
bit = bool(self.mask[where // 8] & (128 >> (where % 8)))
if bit == self.valid_when:
return self.content[where]
else:
return None
elif isinstance(where, slice) and where.step is None:
# In general, slices must convert BitMaskedArray to ByteMaskedArray.
bytemask = np.unpackbits(
self.mask, bitorder=("little" if self.lsb_order else "big")
).view(bool)
return ByteMaskedArray(
bytemask[where.start : where.stop],
self.content[where.start : where.stop],
valid_when=self.valid_when,
)
elif isinstance(where, str):
return BitMaskedArray(
self.mask,
self.content[where],
valid_when=self.valid_when,
length=self.length,
lsb_order=self.lsb_order,
)
else:
raise AssertionError(where)
- ak.contents.BitMaskedArray.mask#
- ak.contents.BitMaskedArray.valid_when#
- ak.contents.BitMaskedArray.lsb_order#
- ak.contents.BitMaskedArray.copy(self, mask=UNSET, content=UNSET, valid_when=UNSET, length=UNSET, lsb_order=UNSET, *, parameters=UNSET)#
- ak.contents.BitMaskedArray.__copy__(self)#
- ak.contents.BitMaskedArray.__deepcopy__(self, memo)#
- ak.contents.BitMaskedArray.simplified(cls, mask, content, valid_when, length, lsb_order, *, parameters=None)#
- ak.contents.BitMaskedArray._form_with_key(self, getkey)#
- ak.contents.BitMaskedArray._to_buffers(self, form, getkey, container, backend, byteorder)#
- ak.contents.BitMaskedArray._to_typetracer(self, forget_length)#
- ak.contents.BitMaskedArray._touch_data(self, recursive)#
- ak.contents.BitMaskedArray._touch_shape(self, recursive)#
- ak.contents.BitMaskedArray.length#
- ak.contents.BitMaskedArray.__repr__(self)#
- ak.contents.BitMaskedArray._repr(self, indent, pre, post)#
- ak.contents.BitMaskedArray.to_IndexedOptionArray64(self)#
- ak.contents.BitMaskedArray.to_ByteMaskedArray(self)#
- ak.contents.BitMaskedArray.to_BitMaskedArray(self, valid_when, lsb_order)#
- ak.contents.BitMaskedArray.mask_as_bool(self, valid_when=None)#
- ak.contents.BitMaskedArray._getitem_nothing(self)#
- ak.contents.BitMaskedArray._is_getitem_at_placeholder(self)#
- ak.contents.BitMaskedArray._getitem_at(self, where)#
- ak.contents.BitMaskedArray._getitem_range(self, start, stop)#
- ak.contents.BitMaskedArray._getitem_field(self, where, only_fields=())#
- ak.contents.BitMaskedArray._getitem_fields(self, where, only_fields=())#
- ak.contents.BitMaskedArray._carry(self, carry, allow_lazy)#
- ak.contents.BitMaskedArray._getitem_next_jagged(self, slicestarts, slicestops, slicecontent, tail)#
- ak.contents.BitMaskedArray._getitem_next(self, head, tail, advanced)#
- ak.contents.BitMaskedArray.project(self, mask=None)#
- ak.contents.BitMaskedArray._offsets_and_flattened(self, axis, depth)#
- ak.contents.BitMaskedArray._mergeable_next(self, other, mergebool)#
- ak.contents.BitMaskedArray._reverse_merge(self, other)#
- ak.contents.BitMaskedArray._mergemany(self, others)#
- ak.contents.BitMaskedArray._fill_none(self, value)#
- ak.contents.BitMaskedArray._local_index(self, axis, depth)#
- ak.contents.BitMaskedArray._numbers_to_type(self, name, including_unknown)#
- ak.contents.BitMaskedArray._is_unique(self, negaxis, starts, parents, outlength)#
- ak.contents.BitMaskedArray._unique(self, negaxis, starts, parents, outlength)#
- ak.contents.BitMaskedArray._argsort_next(self, negaxis, starts, shifts, parents, outlength, ascending, stable)#
- ak.contents.BitMaskedArray._sort_next(self, negaxis, starts, parents, outlength, ascending, stable)#
- ak.contents.BitMaskedArray._combinations(self, n, replacement, recordlookup, parameters, axis, depth)#
- ak.contents.BitMaskedArray._reduce_next(self, reducer, negaxis, starts, shifts, parents, outlength, mask, keepdims, behavior)#
- ak.contents.BitMaskedArray._validity_error(self, path)#
- ak.contents.BitMaskedArray._nbytes_part(self)#
- ak.contents.BitMaskedArray._pad_none(self, target, axis, depth, clip)#
- ak.contents.BitMaskedArray._to_arrow(self, pyarrow, mask_node, validbytes, length, options)#
- ak.contents.BitMaskedArray._to_backend_array(self, allow_missing, backend)#
- ak.contents.BitMaskedArray._remove_structure(self, backend, options)#
- ak.contents.BitMaskedArray._drop_none(self)#
- ak.contents.BitMaskedArray._recursively_apply(self, action, depth, depth_context, lateral_context, options)#
- ak.contents.BitMaskedArray.to_packed(self, recursive=True)#
- ak.contents.BitMaskedArray._to_list(self, behavior, json_conversions)#
- ak.contents.BitMaskedArray._to_backend(self, backend)#
- ak.contents.BitMaskedArray._is_equal_to(self, other, index_dtype, numpyarray, all_parameters)#