ak.layout.IndexedOptionArray¶
The IndexedOptionArray concept is implemented in 2 specialized classes:
ak.layout.IndexOptionArray64:indexvalues 64-bit signed integers.
ak.layout.IndexOptionArray32:indexvalues are 32-bit signed integers.
The IndexedOptionArray class is an ak.layout.IndexedArray for which
negative values in the index are interpreted as missing. It represents
ak.types.OptionType data like ak.layout.ByteMaskedArray,
ak.layout.BitMaskedArray, and ak.layout.UnmaskedArray, but
the flexibility of the arbitrary index makes it a common output of
many operations.
IndexedOptionArray doesn’t have a direct equivalent in Apache Arrow.
Below is a simplified implementation of a IndexedOptionArray class in pure Python
that exhaustively checks validity in its constructor (see
ak.is_valid) and can generate random valid arrays. The
random_number() function returns a random float and the
random_length(minlen) function returns a random int that is at least
minlen. The RawArray class represents simple, one-dimensional data.
class IndexedOptionArray(Content):
def __init__(self, index, content):
assert isinstance(index, list)
assert isinstance(content, Content)
for x in index:
assert isinstance(x, int)
assert x < len(content) # index[i] may be negative
self.index = index
self.content = content
@staticmethod
def random(minlen, choices):
content = random.choice(choices).random(0, choices)
index = []
for i in range(random_length(minlen)):
if len(content) == 0 or random.randint(0, 4) == 0:
index.append(-random_length(1)) # a random number, but not necessarily -1
else:
index.append(random.randint(0, len(content) - 1))
return IndexedOptionArray(index, content)
def __len__(self):
return len(self.index)
def __getitem__(self, where):
if isinstance(where, int):
assert 0 <= where < len(self)
if self.index[where] < 0:
return None
else:
return self.content[self.index[where]]
elif isinstance(where, slice) and where.step is None:
return IndexedOptionArray(self.index[where.start:where.stop], self.content)
elif isinstance(where, str):
return IndexedOptionArray(self.index, self.content[where])
else:
raise AssertionError(where)
def __repr__(self):
return "IndexedOptionArray(" + repr(self.index) + ", " + repr(self.content) + ")"
def xml(self, indent="", pre="", post=""):
out = indent + pre + "<IndexedOptionArray>\n"
out += indent + " <index>" + " ".join(str(x) for x in self.index) + "</index>\n"
out += self.content.xml(indent + " ", "<content>", "</content>\n")
out += indent + "</IndexedOptionArray>\n"
return out
Here is an example:
IndexedOptionArray([-30, 19, 6, 7, -3, 21, 13, 22, 17, 9, -12, 16],
RawArray([5.2, 1.7, 6.7, -0.4, 4.0, 7.8, 3.8, 6.8, 4.2, 0.3, 4.6, 6.2,
6.9, -0.7, 3.9, 1.6, 8.7, -0.7, 3.2, 4.3, 4.0, 5.8, 4.2, 7.0,
5.6, 3.8]))
<IndexedOptionArray>
<index>-30 19 6 7 -3 21 13 22 17 9 -12 16</index>
<content><RawArray>
<ptr>5.2 1.7 6.7 -0.4 4.0 7.8 3.8 6.8 4.2 0.3 4.6 6.2 6.9 -0.7 3.9 1.6 8.7 -0.7 3.2
4.3 4.0 5.8 4.2 7.0 5.6 3.8</ptr>
</RawArray></content>
</IndexedOptionArray>
which represents the following logical data.
[None, 4.3, 3.8, 6.8, None, 5.8, -0.7, 4.2, -0.7, 0.3, None, 8.7]
In addition to the properties and methods described in ak.layout.Content, an IndexedOptionArray has the following.
ak.layout.IndexedOptionArray.__init__¶
- ak.layout.IndexedOptionArray.__init__(index, content, identities=None, parameters=None)¶
ak.layout.IndexedOptionArray.isoption¶
- ak.layout.IndexedOptionArray.isoption¶
Returns True because this is an IndexedOptionArray.
ak.layout.IndexedOptionArray.project¶
- ak.layout.IndexedOptionArray.project(mask=None)¶
Returns a non-ak.types.OptionType array containing only the valid elements
with the index applied to reorder/duplicate elements.
If mask is a signed 8-bit ak.layout.Index in which 0 means valid
and 1 means missing, this mask is unioned with the BitMaskedArray’s
mask (after converting to 8-bit and to valid_when=False to match this mask).
ak.layout.IndexedOptionArray.bytemask¶
- ak.layout.IndexedOptionArray.bytemask()¶
Returns an array of 8-bit values in which 0 means valid and 1 means missing.
ak.layout.IndexedOptionArray.simplify¶
- ak.layout.IndexedOptionArray.simplify()¶
Combines this node with its content if the content also has
ak.types.OptionType or is an ak.layout.IndexedArray; otherwise, this is
a pass-through. In all cases, the output has the same logical meaning as the input.
This method only operates one level deep.