scrapy下载大文件

大文件下载

大文件下载，需要将请求到的数据在管道中进行下载；

依赖：

Pillow模块   安装：pip install Pillow 若安装失败，使用下载地址，下载到本地安装：https://www.lfd.uci.edu/~gohlke/pythonlibs/#_pillow

实例：

需求：将摄图网第一页图片已标题为名称下载到本地保存.jpg格式；

spiders-->img.py

import re

import scrapy

from imgPro.items import ImgproItem


class ImgSpider(scrapy.Spider):
    name = 'img'
    # allowed_domains = ['www.xxx.com']
    start_urls = ['http://699pic.com/image/1']

    def parse(self, response):
        # 解析图片地址和图片名称//*[@id="pins"]/li[1]
        li_list = response.xpath('//div[@class="special-list clearfix"]/div')
        for li in li_list:
            category = li.xpath("./a[@class='special-list-title']/h2/text()").extract_first() + ".jpg"
            url = li.xpath("./div/a/img/@src").extract_first()
            pattern = re.compile("//(.*?)!.*$")  # 定义规则
            rule_list = pattern.findall(url)
            # print("是什么到了这里了啊",rule_list)
            item = ImgproItem()
            for i in range(len(rule_list)):
                item["image_url"] = "https://{0}".format(rule_list[i])
            item["images_name"] = category

            yield item

items.py

# Define here the models for your scraped items
#
# See documentation in:
# https://docs.scrapy.org/en/latest/topics/items.html

import scrapy


class ImgproItem(scrapy.Item):
    # define the fields for your item here like:
    # name = scrapy.Field()
    images_name = scrapy.Field()
    image_url = scrapy.Field()

settings.py

# Scrapy settings for imgPro project
#
# For simplicity, this file contains only settings considered important or
# commonly used. You can find more settings consulting the documentation:
#
#     https://docs.scrapy.org/en/latest/topics/settings.html
#     https://docs.scrapy.org/en/latest/topics/downloader-middleware.html
#     https://docs.scrapy.org/en/latest/topics/spider-middleware.html

BOT_NAME = 'imgPro'

SPIDER_MODULES = ['imgPro.spiders']
NEWSPIDER_MODULE = 'imgPro.spiders'


# Crawl responsibly by identifying yourself (and your website) on the user-agent
#USER_AGENT = 'imgPro (+http://www.yourdomain.com)'

# Obey robots.txt rules
ROBOTSTXT_OBEY = False
LOG_LEVEL = "ERROR"  # 定义只输出错误的日志
USER_AGENT = 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/84.0.4147.105 Safari/537.36'

IMAGES_STORE = "./imgLibs66" # 存储图片的文件夹，存在就直接存储，不存在spider自动创建该文件夹

# Configure maximum concurrent requests performed by Scrapy (default: 16)
#CONCURRENT_REQUESTS = 32

# Configure a delay for requests for the same website (default: 0)
# See https://docs.scrapy.org/en/latest/topics/settings.html#download-delay
# See also autothrottle settings and docs
#DOWNLOAD_DELAY = 3
# The download delay setting will honor only one of:
#CONCURRENT_REQUESTS_PER_DOMAIN = 16
#CONCURRENT_REQUESTS_PER_IP = 16

# Disable cookies (enabled by default)
#COOKIES_ENABLED = False

# Disable Telnet Console (enabled by default)
#TELNETCONSOLE_ENABLED = False

# Override the default request headers:
#DEFAULT_REQUEST_HEADERS = {
#   'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
#   'Accept-Language': 'en',
#}

# Enable or disable spider middlewares
# See https://docs.scrapy.org/en/latest/topics/spider-middleware.html
#SPIDER_MIDDLEWARES = {
#    'imgPro.middlewares.ImgproSpiderMiddleware': 543,
#}

# Enable or disable downloader middlewares
# See https://docs.scrapy.org/en/latest/topics/downloader-middleware.html
#DOWNLOADER_MIDDLEWARES = {
#    'imgPro.middlewares.ImgproDownloaderMiddleware': 543,
#}

# Enable or disable extensions
# See https://docs.scrapy.org/en/latest/topics/extensions.html
#EXTENSIONS = {
#    'scrapy.extensions.telnet.TelnetConsole': None,
#}

# Configure item pipelines
# See https://docs.scrapy.org/en/latest/topics/item-pipeline.html

ITEM_PIPELINES = {
   'imgPro.pipelines.MyImagesPipeline': 1,
   'imgPro.pipelines.ImgproPipeline': 2,
}

# Enable and configure the AutoThrottle extension (disabled by default)
# See https://docs.scrapy.org/en/latest/topics/autothrottle.html
#AUTOTHROTTLE_ENABLED = True
# The initial download delay
#AUTOTHROTTLE_START_DELAY = 5
# The maximum download delay to be set in case of high latencies
#AUTOTHROTTLE_MAX_DELAY = 60
# The average number of requests Scrapy should be sending in parallel to
# each remote server
#AUTOTHROTTLE_TARGET_CONCURRENCY = 1.0
# Enable showing throttling stats for every response received:
#AUTOTHROTTLE_DEBUG = False

# Enable and configure HTTP caching (disabled by default)
# See https://docs.scrapy.org/en/latest/topics/downloader-middleware.html#httpcache-middleware-settings
#HTTPCACHE_ENABLED = True
#HTTPCACHE_EXPIRATION_SECS = 0
#HTTPCACHE_DIR = 'httpcache'
#HTTPCACHE_IGNORE_HTTP_CODES = []
#HTTPCACHE_STORAGE = 'scrapy.extensions.httpcache.FilesystemCacheStorage'

pipelines.py

# Define your item pipelines here
#
# Don't forget to add your pipeline to the ITEM_PIPELINES setting
# See: https://docs.scrapy.org/en/latest/topics/item-pipeline.html


# useful for handling different item types with a single interface
from itemadapter import ItemAdapter

# 管道需要接收item中的图片地址和名称，然后管道中请求到图片的数据对其进行持久化存储
import scrapy


# 该默认管道无法帮助我们请求图片数据，因此该管道就不用了
class ImgproPipeline:
    def process_item(self, item, spider):
        return item


from scrapy.pipelines.images import ImagesPipeline  # 提供数据下载功能


class MyImagesPipeline(ImagesPipeline):
    """重写父类的三个方法，需要在配置文件中配置"""

    # 发送请求,根据图片地址发起请求
    def get_media_requests(self, item, info):
        # 这个方法是在发送下载请求之前调用的，其实这个方法本身就是去发送下载请求的
        yield scrapy.Request(url=item['image_url'], meta={"item": item})

    # 指定图片存储地址
    def file_path(self, request, response=None, info=None, *, item=None):
        # 通过request获取meta
        item = request.meta["item"]
        filePath = item["images_name"]
        return filePath  # 只需要返回图片名称，图片存储需要在settings中添加配置:IMAGES_STORE = "./imgLibs"

    # 将item传递给下一个即将被执行的管道类
    def item_completed(self, results, item, info):
        return item

总结：下载管道类是scrapy封装好的直接使用即可：

from scrapy.pipelines.images import ImagesPipeline
重写该管道类的三个方法：
get_media_requests   对图片地址发起请求
file_path  返回图片名称即可

item_completed 返回item，将其返回给下一个即将被执行的管道类
在配置文件中添加：
IMAGES_STORE = "/dirName"