def __getitem__(self, key, key_id=None, key_var=None):
"""
Returns a specific value by asking the table
for the value.
The numerical key_id or Variable key_var can be given explicitly.
This prevents dictionary lookups below. Just 'key' is either a key_id
or a key_var.
TODO:
- Pull from self.table instead of from self.table.widget_origin?
"""
# Convert from 'key' to the numerical 'key_id'
if key_id is None:
if not isinstance(key, Integral):
key_id = self._domain.index(key)
else:
key_id = key
# Get key_var for the Variable itself.
if key_var is None:
key_var = self.table.domain[key_id]
# Get the value cached in memory.
#value = self._values[keyid]
# ._value has been removed in Orange 3.2
value = RowInstance.__getitem__(self, key=key, key_id=key_id, key_var=key_var)
# A nan means the value is not yet available.
if numpy.isnan(value):
# Pull and cache the value.
# TODO: Pull from self.table.widget_origin?
if self.table.widget_origin is not None:
value = self.table.widget_origin.pull_cell(self.row_index_full, key_var)
elif self.table.table_origin is not None:
value = self.table.table_origin[self.row_index_full][key_var]
# TODO: Is this necessary? Where does the 'int' come from?
if isinstance(value, (int, numpy.float)):
value = float(value)
# Cache the value both in this RowInstance as well as in
# the original table.
# TODO: Can we do everything with only self.table.X?
#self._values[keyid] = value
# ._values is removed in Orange 3.2
RowInstance.__setitem__(self, key_var, value)
# Only cache in self.table if there is a corresponding row there.
# TODO: Should we do this caching here at all? Probably better
# to do this in the LazyTable itself? E.g. preventing this
# pylint warning:
# pylint: disable=protected-access
if self.row_index_materialized is not None:
if 0 <= key_id < len(self._domain.attributes):
self.table.X[self.row_index_materialized][key_id] = value
elif key_id >= len(self._domain.attributes):
self.table._Y[self.row_index_materialized][key_id - len(self.domain.attributes)] = value
else:
self.table._metas = self._metas[-1 - key_id]
val = Value(self._domain[key_id], value)
return val
def __init__(self, table, row_index, region_of_interest_only=False):
"""
Construct a data instance representing the given row of the table.
row_index is the real row of the data set, which might not be the
materialized row.
When region_of_interest_only is set, then the row is only stored
in the table if it's in the region_of_interest. It should only be
necessary to set this flag internally.
TODO:
- Ensure that rows that are not in the region of interest are
removed from memory because saving memory is the reason they are
not appended to the table.
- Perhaps cache whether an instance is in the region of interest
so they can be skipped later.
"""
# The table that this row belongs to, should be a LazyTable instance.
self.table = table
# row_index_full is enough to get the attribute values of this row.
self.row_index_full = row_index
# TODO: A None for row_index_materialized should not happen anymore
# because this is now checked in LazyTable.__getitem__(). However
# this does mean that the in_roi code is not functional anymore.
# Replace all the RoI code with Filters?
# row_index_materialized is used to cache the attribute values in
# memory in self.table.X, Y and metas. It is set to None if there is
# no corresponding row in self.table.
self.row_index_materialized = table.row_mapping.get(self.row_index_full, None)
if self.row_index_materialized is None:
# The row has not yet been stored in the table. We instantiate
# Instance (super of RowInstance) instead of RowInstance because
# there is no corresponding row in memory yet.
# pylint: disable=non-parent-init-called
Instance.__init__(self, table.domain)
# Nevertheless, from this moment on, we can use this
# LazyRowInstance because all attribute values can be retrieved
# on the fly.
if self.in_filters():
# The row is new and within the filter.
# Therefore needs to be added to be appended to self.table
# if it is within the region_of_interest as well.
self_in_region_of_interest = self.in_region_of_interest()
if not region_of_interest_only or self_in_region_of_interest:
# TODO: Replace the region_of_interest with Filters.
# The new row_index_materialized
# will be set to the current length of the table in memory.
# This ensures that the row is inserted at the right place
# (that is, at the end) when appending.
self.row_index_materialized = table.len_instantiated_data()
self.row_index = self.row_index_materialized
self.table.append(self)
self.table.row_mapping[self.row_index_full] = self.row_index_materialized
# A full RowInstance can now be initialized because the row
# is indeed available in the table.
RowInstance.__init__(self, table, self.row_index_materialized)
else:
# This new row is not available in the table, and we'd like
# to keep it this way to conserve memory.
self.row_index_materialized = None
self.row_index = self.row_index_materialized
else:
# This new row is not available in the table, and we'd like
# to keep it this way to conserve memory.
self.row_index_materialized = None
self.row_index = self.row_index_materialized
else:
# The row is already available in the table.
RowInstance.__init__(self, table, self.row_index_materialized)
