我们从Python开源项目中，提取了以下8个代码示例，用于说明如何使用django.utils.functional.partition()。
def send_messages(self, email_messages): if not email_messages: return msg_count = 0 try: client_created = self.open() prepared_messages = [self.prepare_message(message) for message in email_messages] pre_send.send_robust(self.__class__, messages=prepared_messages) responses = self.client.emails.send_batch(*prepared_messages, TrackOpens=self.get_option('TRACK_OPENS')) post_send.send_robust(self.__class__, messages=prepared_messages, response=responses) sent, not_sent = partition(lambda x: x['ErrorCode'] != 0, responses) msg_count = len(sent) if not_sent: self.raise_for_response(not_sent) if client_created: self.close() except Exception as exc: on_exception.send_robust(self.__class__, raw_messages=email_messages, exception=exc) if not self.fail_silently: raise return msg_count
def bulk_create(self, objs, batch_size=None): """ Inserts each of the instances into the database. This does *not* call save() on each of the instances, does not send any pre/post save signals, and does not set the primary key attribute if it is an autoincrement field. """ # So this case is fun. When you bulk insert you don't get the primary # keys back (if it's an autoincrement), so you can't insert into the # child tables which references this. There are two workarounds, 1) # this could be implemented if you didn't have an autoincrement pk, # and 2) you could do it by doing O(n) normal inserts into the parent # tables to get the primary keys back, and then doing a single bulk # insert into the childmost table. Some databases might allow doing # this by using RETURNING clause for the insert query. We're punting # on these for now because they are relatively rare cases. assert batch_size is None or batch_size > 0 if self.model._meta.parents: raise ValueError("Can't bulk create an inherited model") if not objs: return objs self._for_write = True connection = connections[self.db] fields = self.model._meta.local_concrete_fields objs = list(objs) self._populate_pk_values(objs) with transaction.atomic(using=self.db, savepoint=False): if (connection.features.can_combine_inserts_with_and_without_auto_increment_pk and self.model._meta.has_auto_field): self._batched_insert(objs, fields, batch_size) else: objs_with_pk, objs_without_pk = partition(lambda o: o.pk is None, objs) if objs_with_pk: self._batched_insert(objs_with_pk, fields, batch_size) if objs_without_pk: fields = [f for f in fields if not isinstance(f, AutoField)] self._batched_insert(objs_without_pk, fields, batch_size) return objs
def bulk_create(self, objs, batch_size=None): """ Inserts each of the instances into the database. This does *not* call save() on each of the instances, does not send any pre/post save signals, and does not set the primary key attribute if it is an autoincrement field. Multi-table models are not supported. """ # So this case is fun. When you bulk insert you don't get the primary # keys back (if it's an autoincrement), so you can't insert into the # child tables which references this. There are two workarounds, 1) # this could be implemented if you didn't have an autoincrement pk, # and 2) you could do it by doing O(n) normal inserts into the parent # tables to get the primary keys back, and then doing a single bulk # insert into the childmost table. Some databases might allow doing # this by using RETURNING clause for the insert query. We're punting # on these for now because they are relatively rare cases. assert batch_size is None or batch_size > 0 # Check that the parents share the same concrete model with the our # model to detect the inheritance pattern ConcreteGrandParent -> # MultiTableParent -> ProxyChild. Simply checking self.model._meta.proxy # would not identify that case as involving multiple tables. for parent in self.model._meta.get_parent_list(): if parent._meta.concrete_model is not self.model._meta.concrete_model: raise ValueError("Can't bulk create a multi-table inherited model") if not objs: return objs self._for_write = True connection = connections[self.db] fields = self.model._meta.concrete_fields objs = list(objs) self._populate_pk_values(objs) with transaction.atomic(using=self.db, savepoint=False): if (connection.features.can_combine_inserts_with_and_without_auto_increment_pk and self.model._meta.has_auto_field): self._batched_insert(objs, fields, batch_size) else: objs_with_pk, objs_without_pk = partition(lambda o: o.pk is None, objs) if objs_with_pk: self._batched_insert(objs_with_pk, fields, batch_size) if objs_without_pk: fields = [f for f in fields if not isinstance(f, AutoField)] self._batched_insert(objs_without_pk, fields, batch_size) return objs
def bulk_create(self, objs, batch_size=None): """ Inserts each of the instances into the database. This does *not* call save() on each of the instances, does not send any pre/post save signals, and does not set the primary key attribute if it is an autoincrement field (except if features.can_return_ids_from_bulk_insert=True). Multi-table models are not supported. """ # When you bulk insert you don't get the primary keys back (if it's an # autoincrement, except if can_return_ids_from_bulk_insert=True), so # you can't insert into the child tables which references this. There # are two workarounds: # 1) This could be implemented if you didn't have an autoincrement pk # 2) You could do it by doing O(n) normal inserts into the parent # tables to get the primary keys back and then doing a single bulk # insert into the childmost table. # We currently set the primary keys on the objects when using # PostgreSQL via the RETURNING ID clause. It should be possible for # Oracle as well, but the semantics for extracting the primary keys is # trickier so it's not done yet. assert batch_size is None or batch_size > 0 # Check that the parents share the same concrete model with the our # model to detect the inheritance pattern ConcreteGrandParent -> # MultiTableParent -> ProxyChild. Simply checking self.model._meta.proxy # would not identify that case as involving multiple tables. for parent in self.model._meta.get_parent_list(): if parent._meta.concrete_model is not self.model._meta.concrete_model: raise ValueError("Can't bulk create a multi-table inherited model") if not objs: return objs self._for_write = True connection = connections[self.db] fields = self.model._meta.concrete_fields objs = list(objs) self._populate_pk_values(objs) with transaction.atomic(using=self.db, savepoint=False): if (connection.features.can_combine_inserts_with_and_without_auto_increment_pk and self.model._meta.has_auto_field): self._batched_insert(objs, fields, batch_size) else: objs_with_pk, objs_without_pk = partition(lambda o: o.pk is None, objs) if objs_with_pk: self._batched_insert(objs_with_pk, fields, batch_size) if objs_without_pk: fields = [f for f in fields if not isinstance(f, AutoField)] ids = self._batched_insert(objs_without_pk, fields, batch_size) if connection.features.can_return_ids_from_bulk_insert: assert len(ids) == len(objs_without_pk) for obj_without_pk, pk in zip(objs_without_pk, ids): obj_without_pk.pk = pk obj_without_pk._state.adding = False obj_without_pk._state.db = self.db return objs
def bulk_create(self, objs, batch_size=None): """ Inserts each of the instances into the database. This does *not* call save() on each of the instances, does not send any pre/post save signals, and does not set the primary key attribute if it is an autoincrement field (except if features.can_return_ids_from_bulk_insert=True). Multi-table models are not supported. """ # When you bulk insert you don't get the primary keys back (if it's an # autoincrement, except if can_return_ids_from_bulk_insert=True), so # you can't insert into the child tables which references this. There # are two workarounds: # 1) This could be implemented if you didn't have an autoincrement pk # 2) You could do it by doing O(n) normal inserts into the parent # tables to get the primary keys back and then doing a single bulk # insert into the childmost table. # We currently set the primary keys on the objects when using # PostgreSQL via the RETURNING ID clause. It should be possible for # Oracle as well, but the semantics for extracting the primary keys is # trickier so it's not done yet. assert batch_size is None or batch_size > 0 # Check that the parents share the same concrete model with the our # model to detect the inheritance pattern ConcreteGrandParent -> # MultiTableParent -> ProxyChild. Simply checking self.model._meta.proxy # would not identify that case as involving multiple tables. for parent in self.model._meta.get_parent_list(): if parent._meta.concrete_model is not self.model._meta.concrete_model: raise ValueError("Can't bulk create a multi-table inherited model") if not objs: return objs self._for_write = True connection = connections[self.db] fields = self.model._meta.concrete_fields objs = list(objs) self._populate_pk_values(objs) with transaction.atomic(using=self.db, savepoint=False): objs_with_pk, objs_without_pk = partition(lambda o: o.pk is None, objs) if objs_with_pk: self._batched_insert(objs_with_pk, fields, batch_size) if objs_without_pk: fields = [f for f in fields if not isinstance(f, AutoField)] ids = self._batched_insert(objs_without_pk, fields, batch_size) if connection.features.can_return_ids_from_bulk_insert: assert len(ids) == len(objs_without_pk) for obj_without_pk, pk in zip(objs_without_pk, ids): obj_without_pk.pk = pk obj_without_pk._state.adding = False obj_without_pk._state.db = self.db return objs
