5
我有一个Scrapy中的网页抓取工具,可以获取数据项。我想异步地将它们插入到数据库中。无阻塞Scrapy管道到数据库
例如,我有一些插入项目到我的数据库使用SQLAlchemy的核心事务:
def process_item(self, item, spider):
with self.connection.begin() as conn:
conn.execute(insert(table1).values(item['part1'])
conn.execute(insert(table2).values(item['part2'])
我的理解,它可能与扭曲的异步使用SQLAlchemy核心与alchimia
。下面是alchimia
的文档代码示例。
我不明白的是如何在alchimia框架中使用我的上述代码。我如何设置process_item
使用反应堆?
我可以这样做吗?
@inlineCallbacks
def process_item(self, item, spider):
with self.connection.begin() as conn:
yield conn.execute(insert(table1).values(item['part1'])
yield conn.execute(insert(table2).values(item['part2'])
如何写入反应器部件?
或者是否有一种更简单的方法在Scrapy管道中执行非阻塞数据库插入?
仅供参考,下面是alchimia
的文档中的代码示例:
from alchimia import TWISTED_STRATEGY
from sqlalchemy import (
create_engine, MetaData, Table, Column, Integer, String
)
from sqlalchemy.schema import CreateTable
from twisted.internet.defer import inlineCallbacks
from twisted.internet.task import react
@inlineCallbacks
def main(reactor):
engine = create_engine(
"sqlite://", reactor=reactor, strategy=TWISTED_STRATEGY
)
metadata = MetaData()
users = Table("users", metadata,
Column("id", Integer(), primary_key=True),
Column("name", String()),
)
# Create the table
yield engine.execute(CreateTable(users))
# Insert some users
yield engine.execute(users.insert().values(name="Jeremy Goodwin"))
yield engine.execute(users.insert().values(name="Natalie Hurley"))
yield engine.execute(users.insert().values(name="Dan Rydell"))
yield engine.execute(users.insert().values(name="Casey McCall"))
yield engine.execute(users.insert().values(name="Dana Whitaker"))
result = yield engine.execute(users.select(users.c.name.startswith("D")))
d_users = yield result.fetchall()
# Print out the users
for user in d_users:
print "Username: %s" % user[users.c.name]
if __name__ == "__main__":
react(main, [])