python爬虫入门（九）Scrapy框架之数据库保存

豆瓣电影TOP 250爬取-->>>数据保存到MongoDB

豆瓣电影TOP 250网址



要求：

1.爬取豆瓣top 250电影名字、演员列表、评分和简介

2.设置随机UserAgent和Proxy

3.爬取到的数据保存到MongoDB数据库

items.py

# -*- coding: utf-8 -*-

import scrapy

class DoubanItem(scrapy.Item):
# define the fields for your item here like:
# 标题
title = scrapy.Field()
# 信息
bd = scrapy.Field()
# 评分
star = scrapy.Field()
# 简介
quote = scrapy.Field()

doubanmovie.py

# -*- coding: utf-8 -*-
import scrapy
from douban.items import DoubanItem

class DoubamovieSpider(scrapy.Spider):
name = "doubanmovie"
allowed_domains = ["movie.douban.com"]
offset = 0
url = "https://movie.douban.com/top250?start="
start_urls = (
url+str(offset),
)

def parse(self, response):
item = DoubanItem()
movies = response.xpath("//div[@class='info']")

for each in movies:
# 标题
item['title'] = each.xpath(".//span[@class='title'][1]/text()").extract()[0]
# 信息
item['bd'] = each.xpath(".//div[@class='bd']/p/text()").extract()[0]
# 评分
item['star'] = each.xpath(".//div[@class='star']/span[@class='rating_num']/text()").extract()[0]
# 简介
quote = each.xpath(".//p[@class='quote']/span/text()").extract()
if len(quote) != 0:
item['quote'] = quote[0]
yield item

if self.offset < 225:
self.offset += 25
yield scrapy.Request(self.url + str(self.offset), callback = self.parse)

pipelines.py

# -*- coding: utf-8 -*-

import pymongo
from scrapy.conf import settings

class DoubanPipeline(object):
def __init__(self):
host = settings["MONGODB_HOST"]
port = settings["MONGODB_PORT"]
dbname = settings["MONGODB_DBNAME"]
sheetname= settings["MONGODB_SHEETNAME"]

# 创建MONGODB数据库链接
client = pymongo.MongoClient(host = host, port = port)
# 指定数据库
mydb = client[dbname]
# 存放数据的数据库表名
self.sheet = mydb[sheetname]

def process_item(self, item, spider):
data = dict(item)
self.sheet.insert(data)
return item

settings.py

DOWNLOAD_DELAY = 2.5

COOKIES_ENABLED = False

DOWNLOADER_MIDDLEWARES = {
'douban.middlewares.RandomUserAgent': 100,
'douban.middlewares.RandomProxy': 200,
}

USER_AGENTS = [
'Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.0)',
'Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.2)',
'Opera/9.27 (Windows NT 5.2; U; zh-cn)',
'Opera/8.0 (Macintosh; PPC Mac OS X; U; en)',
'Mozilla/5.0 (Macintosh; PPC Mac OS X; U; en) Opera 8.0',
'Mozilla/5.0 (Linux; U; Android 4.0.3; zh-cn; M032 Build/IML74K) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Mobile Safari/534.30',
'Mozilla/5.0 (Windows; U; Windows NT 5.2) AppleWebKit/525.13 (KHTML, like Gecko) Chrome/0.2.149.27 Safari/525.13'
]

PROXIES = [
{"ip_port" :"121.42.140.113:16816", "user_passwd" : "****"},
#{"ip_prot" :"121.42.140.113:16816", "user_passwd" : ""}
#{"ip_prot" :"121.42.140.113:16816", "user_passwd" : ""}
#{"ip_prot" :"121.42.140.113:16816", "user_passwd" : ""}
]

ITEM_PIPELINES = {
'douban.pipelines.DoubanPipeline': 300,
}

# MONGODB 主机名
MONGODB_HOST = "127.0.0.1"

# MONGODB 端口号
MONGODB_PORT = 27017

# 数据库名称
MONGODB_DBNAME = "Douban"

# 存放数据的表名称
MONGODB_SHEETNAME = "doubanmovies"

middlewares.py

#!/usr/bin/env python
# -*- coding:utf-8 -*-

import random
import base64

from settings import USER_AGENTS
from settings import PROXIES

# 随机的User-Agent
class RandomUserAgent(object):
def process_request(self, request, spider):
useragent = random.choice(USER_AGENTS)
#print useragent
request.headers.setdefault("User-Agent", useragent)

class RandomProxy(object):
def process_request(self, request, spider):
proxy = random.choice(PROXIES)

if proxy['user_passwd'] is None:
# 没有代理账户验证的代理使用方式
request.meta['proxy'] = "http://" + proxy['ip_port']

else:
# 对账户密码进行base64编码转换
base64_userpasswd = base64.b64encode(proxy['user_passwd'])
# 对应到代理服务器的信令格式里
request.headers['Proxy-Authorization'] = 'Basic ' + base64_userpasswd

request.meta['proxy'] = "http://" + proxy['ip_port']