def project_second(self, *fields):
"""
Initiates a ProjectJoin transformation.
Projects the second join input.
If the second join input is a Tuple DataSet, fields can be selected by their index.
If the second join input is not a Tuple DataSet, no parameters should be passed.
:param fields: The indexes of the selected fields.
:return: An incomplete JoinProjection.
"""
if self._info[_Fields.DISCARD2]:#key-selector usedused
self._info[_Fields.OTHER][_Fields.OPERATOR]._pair = False
type = self._info[_Fields.OTHER][_Fields.TYPES]
self._info[_Fields.OTHER][_Fields.TYPES] = concat(type[0], type[1])
if len(fields) == 0:#adjust index
return self.project_second(1)
else:
fields = tuple(map(lambda x: x+1, fields))
self._info[_Fields.PROJECTIONS].append(("second", fields))
return self
def _collect_append(self, value):
self._collector.collect(concat(self.get_key(value), value))
def _run_append(self):
collector = self._collector
for value in self._iterator:
collector.collect(concat(self.get_key(value), value))
collector._close()