数据持久化存储

一数据持久化存储-csv文件

1.作用

　　将爬取的数据存放到本地的csv文件中

2.使用流程

1、导入模块
2、打开csv文件
3、初始化写入对象
4、写入数据(参数为列表)
import csv 

with open('film.csv','w') as f:
    writer = csv.writer(f)
    writer.writerow([])
    writer.writerows([(),(),()])

3.示例代码

创建text.csv文件,在文件中写入数据

# 单行写入（writerow([]))
import csv
with open('test.csv','w',newline='') as f:
    writer = csv.writer(f)
    writer.writerow(['步惊云','36'])
    writer.writerow(['聂风','36'])

# 多行写入(writerows([(),(),()]
import csv
with open('test.csv','w') as f:
    writer = csv.writer(f)
    writer.writerows([('聂风','36'),('秦霜','25'),('孔慈','30')])

练习:猫眼电影数据存入本地 maoyanfilm.csv 文件 - 使用writerow方法实现

思考：使用 writerows()方法实现？

import csv
from urllib import request, parse
import re
import time
import random
from useragents import ua_list


class MaoyanSpider(object):
  def __init__(self):
    self.url = 'https://maoyan.com/board/4?offset={}'
    # 计数
    self.num = 0


  def get_html(self, url):
    headers = {
      'User-Agent': random.choice(ua_list)
    }
    req = request.Request(url=url, headers=headers)
    res = request.urlopen(req)
    html = res.read().decode('utf-8')
    # 直接调用解析函数
    self.parse_html(html)

  def parse_html(self, html):
    # 创建正则的编译对象
    re_ = '<div class="movie-item-info">.*?title="(.*?)".*?<p class="star">(.*?)</p>.*?<p class="releasetime">(.*?)</p> '
    pattern = re.compile(re_, re.S)
    # film_list:[('霸王别姬','张国荣','1993')]
    film_list = pattern.findall(html)
    self.write_html(film_list)

  # 存入csv文件-writerrows
  def write_html(self, film_list):
    L = []
    with open('maoyanfilm.csv', 'a',newline='') as f:
      # 初始化写入对象,注意参数f不能忘
      writer = csv.writer(f)
      for film in film_list:
        t = (
          film[0].strip(),
          film[1].strip(),
          film[2].strip()[5:15]
        )
        self.num += 1
        L.append(t)
      # writerow()参数为列表
      writer.writerows(L)
      print(L)

  # def write_html(self,film_list):
  #   with open('maoyanfilm.csv','a') as f:
  #     #初始化写入对象,注意参数f不能忘
  #     writer=csv.writer(f)
  #     for film in film_list:
  #       L=[
  #         film[0].strip(),
  #         film[1].strip(),
  #         film[2].strip()[5:15]
  #       ]
  #       self.num+=1
  #       # writerow()参数为列表
  #       writer.writerow(L)

  def main(self):
    for offset in range(0, 91, 10):
      url = self.url.format(offset)
      self.get_html(url)
      time.sleep(random.randint(1, 2))
    print('共抓取数据', self.num, "部")


if __name__ == '__main__':
  start = time.time()
  spider = MaoyanSpider()
  spider.main()
  end = time.time()
  print('执行时间:%.2f' % (end - start))

ua_list = [
  'Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; WOW64; Trident/5.0)',
  'Mozilla/5.0 (Windows NT 6.1; WOW64; rv:6.0) Gecko/20100101 Firefox/6.0',
  'Mozilla/5.0 (Windows NT 6.1) AppleWebKit/535.1 (KHTML, like Gecko) Chrome/13.0.782.41 Safari/535.1 QQBrowser/6.9.11079.201',
  'Opera/9.80 (Windows NT 6.1; U; zh-cn) Presto/2.9.168 Version/11.50',

]

二数据持久化存储 - MySQL数据库

1.在数据库中建库建表

# 连接到mysql数据库
mysql -h127.0.0.1 -uroot -p123456
# 建库建表
create database maoyandb charset utf8;
use maoyandb;
create table filmtab(
name varchar(100),
star varchar(300),
time varchar(50)
)charset=utf8;

2.回顾pymysql基本使用

import pymysql

# 创建2个对象
db = pymysql.connect('localhost','root','123456','maoyandb',charset='utf8')
cursor = db.cursor()

# 执行SQL命令并提交到数据库执行
# execute()方法第二个参数为列表传参补位
cursor.execute('insert into filmtab values(%s,%s,%s)',['霸王别姬','张国荣','1993'])
db.commit()

# 关闭
cursor.close()
db.close()

3.来试试高效的executemany()方法？

import pymysql

# 创建2个对象
db = pymysql.connect('192.168.153.137','tiger','123456','maoyandb',charset='utf8')
cursor = db.cursor()

# 抓取的数据
film_list = [('月光宝盒','周星驰','1994'),('大圣娶亲','周星驰','1994')]

# 执行SQL命令并提交到数据库执行
# execute()方法第二个参数为列表传参补位
cursor.executemany('insert into filmtab values(%s,%s,%s)',film_list)
db.commit()

# 关闭
cursor.close()
db.close()

import pymysql

# __init__(self)：
    self.db = pymysql.connect('IP',... ...)
    self.cursor = self.db.cursor()
# write_data(self):
    self.cursor.execute('sql',[data1])
    self.cursor.executemany('sql',[(data1),(data2),(data3)])
    self.db.commit()
# main(self):
    self.cursor.close()
    self.db.close()

4.将电影信息存入MySQL数据库（尽量使用executemany方法）

import pymysql
from urllib import request, parse
import re
import time
import random
from useragents import ua_list


class MaoyanSpider(object):
  def __init__(self):
    self.url = 'https://maoyan.com/board/4?offset={}'
    # 计数
    self.num = 0
    self.db = pymysql.connect(
      'localhost', 'root', '123456', 'maoyandb', charset='utf8'
    )
    self.cursor = self.db.cursor()

  def get_html(self, url):
    headers = {
      'User-Agent': random.choice(ua_list)
    }
    req = request.Request(url=url, headers=headers)
    res = request.urlopen(req)
    html = res.read().decode('utf-8')
    # 直接调用解析函数
    self.parse_html(html)

  def parse_html(self, html):
    # 创建正则的编译对象
    re_ = '<div class="movie-item-info">.*?title="(.*?)".*?<p class="star">(.*?)</p>.*?<p class="releasetime">(.*?)</p> '
    pattern = re.compile(re_, re.S)
    # film_list:[('霸王别姬','张国荣','1993')]
    film_list = pattern.findall(html)
    self.write_html(film_list)

  def write_html(self, film_list):
    ins = 'insert into filmtab values(%s,%s,%s)'
    for film in film_list:
      L = [
        film[0].strip(),
        film[1].strip(),
        film[2].strip()[5:15]
      ]
      self.num+=1
      print('爬取成功',self.num,'部')
      self.cursor.execute(ins, L)
      #提交到数据库执行
      self.db.commit()

  def main(self):
    for offset in range(0, 91, 10):
      url = self.url.format(offset)

      self.get_html(url)
      time.sleep(random.randint(1, 2))
    print('共抓取数据', self.num, "部")
    # 断开数据库
    self.cursor.close()
    self.db.close()


if __name__ == '__main__':
  start = time.time()
  spider = MaoyanSpider()
  spider.main()
  end = time.time()
  print('执行时间:%.2f' % (end - start))

import pymysql
from urllib import request, parse
import re
import time
import random
from useragents import ua_list


class MaoyanSpider(object):
  def __init__(self):
    self.url = 'https://maoyan.com/board/4?offset={}'
    # 计数
    self.num = 0
    self.db = pymysql.connect(
      'localhost', 'root', '123456', 'maoyandb', charset='utf8'
    )
    self.cursor = self.db.cursor()

  def get_html(self, url):
    headers = {
      'User-Agent': random.choice(ua_list)
    }
    req = request.Request(url=url, headers=headers)
    res = request.urlopen(req)
    html = res.read().decode('utf-8')
    # 直接调用解析函数
    self.parse_html(html)

  def parse_html(self, html):
    # 创建正则的编译对象
    re_ = '<div class="movie-item-info">.*?title="(.*?)".*?<p class="star">(.*?)</p>.*?<p class="releasetime">(.*?)</p> '
    pattern = re.compile(re_, re.S)
    # film_list:[('霸王别姬','张国荣','1993')]
    film_list = pattern.findall(html)
    self.write_html(film_list)
  #mysql-executemany
  def write_html(self, film_list):
    L=[]
    ins = 'insert into filmtab values(%s,%s,%s)'
    for film in film_list:
      t = [
        film[0].strip(),
        film[1].strip(),
        film[2].strip()[5:15]
      ]
      self.num+=1
      L.append(t)
      print('爬取成功',self.num,'部')
    self.cursor.executemany(ins, L)
    #提交到数据库执行
    self.db.commit()

  def main(self):
    for offset in range(0, 91, 10):
      url = self.url.format(offset)

      self.get_html(url)
      time.sleep(random.randint(1, 2))
    print('共抓取数据', self.num, "部")
    # 断开数据库
    self.cursor.close()
    self.db.close()


if __name__ == '__main__':
  start = time.time()
  spider = MaoyanSpider()
  spider.main()
  end = time.time()
  print('执行时间:%.2f' % (end - start))

5.做个SQL查询

1、查询20年以前的电影的名字和上映时间
   select name,time from film where time<=(now()-interval 20 year);
2、查询1990-2000年的电影名字和上映时间
   select name,time from film where time>='1990-01-01' and time<='2000-12-31';

 三数据持久化存储-MongoDB数据库

(一)特点

　　1.非关系型数据库

　　2.库/集合(MySQL中表),文档(MySQL中表记录)

　　3.无须手动建库建集合

　　4.基本命令

#查看所有的库
    >show dbs
#切换库
    >use 库名
#查看库中所有的集合
    >show collections
#查看集合中所有文档
    >db.集合名.find().pretty()
#统计集合中文档个数
    >db.集合名.count()

(二)pymongo操作mongodb数据库

import pymongo
#1.连接对象
conn = pymongo.MongoClient(
  host='127.0.0.1',
  port=27017
)
#2.库对象
db = conn['maoyandb'] #第一种方法
# db = conn.maoyandb  #第二种方法
#3.集合对象
myset = db['filmtab']
#4.插入数据库
#插入一个
myset.insert_one({'name':'赵敏'})
#插入多个
myset.insert_many()

import pymongo

# __init__(self)：
    self.conn = pymongo.MongoClient('IP',27017)
    self.db = self.conn['db_name']
    self.myset = self.db['set_name']
# write_data(self):
    self.myset.insert_one(dict)

# MongoDB - Commmand
>show dbs
>use db_name
>show collections
>db.collection_name.find().pretty()
>db.collection_name.count()
>db.collection_name.drop()
>db.dropDatabase()

练习:将电影信息存入MongoDB数据库

import pymongo
from urllib import request
import re
import time
import random
from useragents import ua_list


class MaoyanSpider(object):
  def __init__(self):
    self.url = 'https://maoyan.com/board/4?offset={}'
    # 计数
    self.num = 0
    # 创建3个对象
    self.conn = pymongo.MongoClient(host='127.0.0.1',port=27017)
    self.db = self.conn['maoyandb']
    self.myset = self.db['filmset']

  def get_html(self, url):
    headers = {
      'User-Agent': random.choice(ua_list)
    }
    req = request.Request(url=url, headers=headers)
    res = request.urlopen(req)
    html = res.read().decode('utf-8')
    # 直接调用解析函数
    self.parse_html(html)

  def parse_html(self, html):
    # 创建正则的编译对象
    re_ = '<div class="movie-item-info">.*?title="(.*?)".*?<p class="star">(.*?)</p>.*?<p class="releasetime">(.*?)</p> '
    pattern = re.compile(re_, re.S)
    # film_list:[('霸王别姬','张国荣','1993')]
    film_list = pattern.findall(html)
    self.write_html(film_list)

  # mysql-executemany
  def write_html(self, film_list):
    for film in film_list:
      film_dict = {
        'name':film[0].strip(),
        'star':film[1].strip(),
        'time':film[2].strip()[5:15]
      }
      self.num+=1
      #插入mongodb数据库
      self.myset.insert_one(film_dict)
      print('爬取成功', self.num, '部')


  def main(self):
    for offset in range(0, 91, 10):
      url = self.url.format(offset)

      self.get_html(url)
      time.sleep(random.randint(1, 2))
    print('共抓取数据', self.num, "部")


if __name__ == '__main__':
  start = time.time()
  spider = MaoyanSpider()
  spider.main()
  end = time.time()
  print('执行时间:%.2f' % (end - start))

多级页面数据抓取

# 整体思路 
1、爬取一级页面,提取 所需数据+链接,继续跟进
2、爬取二级页面,提取 所需数据+链接,继续跟进
3、... ... 
# 代码实现思路
1、所有数据最终都会在一级页面解析函数中拿到
2、避免重复代码 - 请求、解析需定义函数

电影天堂案例 - 二级页面抓取

领取任务:

# 地址
电影天堂 - 2019年新片精品 - 更多
# 目标
电影名称、下载链接

# 分析
*********一级页面需抓取***********
        1、电影名称
        2、电影链接
        
*********二级页面需抓取***********
        1、下载链接

实现步骤:

　　1、确定响应内容中是否存在所需抓取数据

　　2、找URL规律

第1页 ：https://www.dytt8.net/html/gndy/dyzz/list_23_1.html
第2页 ：https://www.dytt8.net/html/gndy/dyzz/list_23_2.html
第n页 ：https://www.dytt8.net/html/gndy/dyzz/list_23_n.html

写正则表达式:

1、一级页面正则表达式
   <table width="100%".*?<td width="5%".*?<a href="(.*?)".*?ulink">(.*?)</a>.*?</table>
2、二级页面正则表达式
   <td style="WORD-WRAP.*?>.*?>(.*?)</a>

 代码实现:

import csv
from urllib import request
import re
from useragents import ua_list
import time
import random


class FilmSkySpider(object):
  def __init__(self):
    self.url = 'https://www.dytt8.net/html/gndy/dyzz/list_23_{}.html'

  # 获取相应内容
  def get_html(self, url):
    headers = {'User-Agent': random.choice(ua_list)}
    req = request.Request(url=url, headers=headers)
    res = request.urlopen(req)
    #通过网站查看网页远吗,查看网站charset='gb2312'
    #如果遇到解码错误,识别不了一些字符,则 ignore
    html = res.read().decode('gb2312','ignore')
    return html

  # 正则解析功能函数
  def re_func(self, re_bds, html):
    pattern = re.compile(re_bds, re.S)
    r_list = pattern.findall(html)
    return r_list
  # 获取数据函数 html是一级页面相应内容
  def parse_page(self, html):
    # 想办法获取到 电影名称和下载链接
    re_bds = r'<table width="100%".*?<td width="5%".*?<a href="(.*?)".*?ulink">(.*?)</a>.*?</table>'
    # one_page_list:[('/html/xxx','幸福猎人'),()]
    one_page_list = self.re_func(re_bds, html)
    with open('movefilm.csv', 'a', newline='') as f:
      # 初始化写入对象,注意参数f不能忘
      writer = csv.writer(f)
      item = {}
      for film in one_page_list:
          item['name'] = film[1].strip()
          link = 'https://www.dytt8.net' + film[0]
          item['download'] = self.parse_two_page(link)
          time.sleep(random.uniform(1, 3))
          print(item)
      writer.writerows(item)

  # 解析二级页面数据
  def parse_two_page(self, link):
    html = self.get_html(link)
    re_bds = r'<td style="WORD-WRAP.*?>.*?>(.*?)</a>'
    # two_page_list:['ftp://xxxx.mkv']
    two_page_list = self.re_func(re_bds, html)
    download = two_page_list[0].strip()
    return download

  def main(self):
    for page in range(1, 11):
      url = self.url.format(page)
      html = self.get_html(url)
      self.parse_page(html)



if __name__ == '__main__':
  start = time.time()
  spider = FilmSkySpider()
  spider.main()
  end = time.time()
  print('执行时间:%.2f' % (end - start))

练习:把电影天堂数据存入MySQL数据库