Python 服务器是否可以读取由scrapy发送的请求元数据？

下面的代码基本上是亚马逊蜘蛛的一个示例
我想知道amazon服务器（或任何其他服务器）是否可以知道我们将哪些数据传递到scrapy Request.meta。如果Request.meta没有与我们的请求一起传递，那么我们如何将元数据接收到response.meta中。

有人能解释一下request.meta和response.meta是如何工作的吗

import random
from HTMLParser import HTMLParser

import scrapy
from scrapy.crawler import CrawlerProcess

import os
import sys

sys.path.append(os.path.abspath(os.path.join(os.path.dirname(__file__), '../..')))
from amazon.items import AmazonItem
from amazon.user_agents import user_agent_list


class MLStripper(HTMLParser):
    def __init__(self):
        self.reset()
        self.fed = []

    def handle_data(self, d):
        self.fed.append(d)

    def get_data(self):
        return ''.join(self.fed)

    def strip_tags(html):
        s = MLStripper()
        s.feed(html)
        return s.get_data()


class Amazon(scrapy.Spider):
    allowed_domains = ['amazon.in']
    start_urls = ['http://www.amazon.in']
    name = 'amazon'

    def parse(self, response):
        product_detail = response.xpath('//li[@class="s-result-item  celwidget "]')
        for product in product_detail:
            asin = product.xpath('@data-asin').extract_first().encode('ascii', 'ignore')
            url = 'http://www.amazon.in/dp/' + asin
            brand = product.xpath('div/div/div/span[2]/text()').extract_first()
            if brand != 'Azani':
                request = scrapy.Request(url, callback=self.parse_product)
                request.meta['asin'] = asin
                yield request

            next_page = response.xpath('//a[@id="pagnNextLink"]/@href').extract_first()
            if next_page:
                next_page = 'http://www.amazon.in' + next_page
                request = scrapy.Request(next_page, callback=self.parse)
                yield request

    def offer_page(self, response):
        item = response.meta['item']
        seller = response.xpath('//div[@class="a-row a-spacing-mini olpOffer"]/div/h3/span/a/text()').extract()
        price = response.xpath('//div[@class="a-row a-spacing-mini olpOffer"]/div/span/span/text()').extract()
        seller_price = zip(seller, price)
        item['brand'] = response.xpath('//div[@id="olpProductByline"]/text()').extract_first().strip().replace('by ',
                                                                                                               '')
        item['price'] = '{}'.format(seller_price)
        item['no_of_seller'] = len(seller_price)
        yield item

    def parse_product(self, response):
        def html_to_text(html):
            s = MLStripper()
            s.feed(html)
            return s.get_data()

        asin = response.meta['asin']
        item = AmazonItem()
        item['asin'] = asin
        item['product_name'] = response.xpath('//*[@id="productTitle"]/text()').extract_first().strip()
        item['bullet_point'] = html_to_text(
            response.xpath('//*[@id="feature-bullets"]').extract_first()).strip()
        item['description'] = html_to_text(response.xpath('//*[@id="productDescription"]').extract_first()).strip()
        child_asins = response.xpath('//*[@class="dropdownAvailable"]/@value').extract()
        child_asins = map(lambda x: x.split(',')[-1], child_asins)
        child_asins = ','.join(child_asins)
        item['child_asin'] = child_asins.encode('utf-8', 'ignore')
        offer_page = 'http://www.amazon.in/gp/offer-listing/' + asin
        request = scrapy.Request(offer_page, callback=self.offer_page)
        request.meta['item'] = item
        yield request

没有

您可以通过检查

request.body

和

request.headers

属性来查看请求发送到源代码的内容

$ scrapy shell "http://stackoverflow.com"
>[1]: request.headers
<[1]: 
{b'Accept': b'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
 b'Accept-Encoding': b'gzip,deflate',
 b'Accept-Language': b'en',
 b'User-Agent': b'scrapy'}
>[2]: request.body
<[2]: b''
>[3]: request.method
<[3]: 'GET'

$scrapy shell”http://stackoverflow.com"
>[1] ：request.headers
[2] ：request.body
[3] ：request.method