将 url 传递到从 RabbitMQ 使用的 scrapy 中的解析方法

Question

我正在使用 scrapy 来消费来自 RabbitMQ 的消息 (url)，但是当我使用 yield 调用解析方法时将我的 url 作为参数传递。程序没有进入回调 method.Below 是我的蜘蛛的以下代码

# -*- coding: utf-8 -*-
import scrapy
import pika
from scrapy import cmdline
import json

class MydeletespiderSpider(scrapy.Spider):
    name = 'Mydeletespider'
    allowed_domains = []
    start_urls = []

def callback(self,ch, method, properties, body):
    print(" [x] Received %r" % body)
    body=json.loads(body)
    url=body.get('url')
    yield scrapy.Request(url=url,callback=self.parse)

def start_requests(self):
    cre = pika.PlainCredentials('test', 'test')
    connection = pika.BlockingConnection(
        pika.ConnectionParameters(host='10.0.12.103', port=5672, credentials=cre, socket_timeout=60))
    channel = connection.channel()



    channel.basic_consume(self.callback,
                          queue='Deletespider_Batch_Test',
                          no_ack=True)


    print(' [*] Waiting for messages. To exit press CTRL+C')
    channel.start_consuming()

def parse(self, response):
    print response.url
    pass

cmdline.execute('scrapy crawl Mydeletespider'.split())

我的目标是将 url 响应传递给解析方法

Answer 1

要使用来自 rabbitmq 的 url，您可以查看 scrapy-rabbitmq 包：

Scrapy-rabbitmq is a tool that lets you feed and queue URLs from RabbitMQ via Scrapy spiders, using the Scrapy framework.

要启用它，请在 settings.py:

中设置这些值

# Enables scheduling storing requests queue in rabbitmq.
SCHEDULER = "scrapy_rabbitmq.scheduler.Scheduler"
# Don't cleanup rabbitmq queues, allows to pause/resume crawls.
SCHEDULER_PERSIST = True
# Schedule requests using a priority queue. (default)
SCHEDULER_QUEUE_CLASS = 'scrapy_rabbitmq.queue.SpiderQueue'
# RabbitMQ Queue to use to store requests
RABBITMQ_QUEUE_NAME = 'scrapy_queue'
# Provide host and port to RabbitMQ daemon
RABBITMQ_CONNECTION_PARAMETERS = {'host': 'localhost', 'port': 6666}

# Bonus:
# Store scraped item in rabbitmq for post-processing.
# ITEM_PIPELINES = {
#    'scrapy_rabbitmq.pipelines.RabbitMQPipeline': 1
# }

在你的蜘蛛中：

from scrapy import Spider
from scrapy_rabbitmq.spiders import RabbitMQMixin

class RabbitSpider(RabbitMQMixin, Spider):
    name = 'rabbitspider'

    def parse(self, response):
        # mixin will take urls from rabbit queue by itself
        pass

Answer 2

参考这个：http://30daydo.com/article/512

def start_requests(self) 这个函数应该 return 一个生成器，否则 scrapy 将无法工作。

将 url 传递到从 RabbitMQ 使用的 scrapy 中的解析方法

Pass the url into the parse method in scrapy that was consumed from RabbitMQ

yield

rabbitmq

scrapy

web-scraping

pika