本次爬取用到的知识点有:
- selenium
- pymysql
- pyquery
正文
-
分析目标网站
-
打开某宝首页, 输入"男装"后点击"搜索", 则跳转到"男装"的搜索界面.
-
空白处"右击"再点击"检查"审查网页元素, 点击"Network".
-
找到对应的URL, URL里的参数正是Query String Parameters的参数, 且请求方式是GET
-
我们请求该URL得到内容就是"Response"里的内容, 那么点击它来确认信息.
-
下拉看到"男装"字样, 那么再往下找, 并没有发现有关"男装"的商品信息.
-
任意复制一个商品信息, 空白处右击再点击"查看网页源代码", 在源码查找该商品, 即可看到该商品的信息.
-
对比网页源代码和"Response"响应内容, 发现源代码中的商品信息被替换, 这便是采用了JS加密
-
如果去请求上面的URL, 得到的则是加密过的信息, 这时就可以利用Selenium库来模拟浏览器, 进而得到商品信息.
获取单个商品界面
- 请求网站
# -*- coding: utf-8 -*-
from selenium import webdriver #从selenium导入浏览器驱动
'''
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'''
browser = webdriver.Chrome() #声明驱动对象, 即Chrome浏览器
def get_one_page():
'''获取单个页面'''
browser.get("https://www.xxxxx.com") #请求网站
- 输入"男装", 在输入之前, 需要判断输入框是否存在, 如果存在则输入"男装", 不存在则等待显示成功.
# -*- coding: utf-8 -*-
from selenium import webdriver
from selenium.webdriver.common.by import By #导入元素定位方法模块
from selenium.webdriver.support.ui import WebDriverWait #导入等待判断模块
from selenium.webdriver.support import expected_conditions as EC #导入判断条件模块
browser = webdriver.Chrome()
def get_one_page():
'''获取单个页面'''
browser.get("https://www.xxxxx.com")
input = WebDriverWait(browser,10).until( #等待判断
EC.presence_of_element_located((By.CSS_SELECTOR,"#q"))) #若输入框显示成功,则获取,否则等待
input.send_keys("男装") #输入商品名称
- 下一步就是点击"搜索"按钮, 按钮具有属性: 可点击, 那么加入判断条件.
# -*- coding: utf-8 -*-
from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC
browser = webdriver.Chrome()
def get_one_page():
'''获取单个页面'''
browser.get("https://www.xxxxx.com")
input = WebDriverWait(browser,10).until(
EC.presence_of_element_located((By.CSS_SELECTOR,"#q"))) #
input.send_keys("男装")
button = WebDriverWait(browser,10).until( #等待判断
EC.element_to_be_clickable((By.CSS_SELECTOR,"#J_TSearchForm > div.search-button > button"))) #若按钮可点击, 则获取, 否则等待
button.click()
- 获取总的页数, 同样加入等待判断.
# -*- coding: utf-8 -*-
import re
from selenium import webdriver
from selenium.common.exceptions import TimeoutException
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC
browser = webdriver.Chrome()
def get_one_page():
'''获取单个页面'''
browser.get("https://www.xxxxx.com")
input = WebDriverWait(browser, 10).until(
EC.presence_of_element_located((By.CSS_SELECTOR, "#q")))
input.send_keys("男装")
button = WebDriverWait(browser, 10).until(
EC.element_to_be_clickable(
(By.CSS_SELECTOR, "#J_TSearchForm > div.search-button > button")))
button.click()
pages = WebDriverWait(browser, 10).until( # 等待判断
EC.presence_of_element_located(
(By.CSS_SELECTOR, "#mainsrp-pager > div > div > div > div.total"))) # 若总页数加载成功,则获取总页数,否则等待
return pages.text
def main():
pages = get_one_page()
print(pages)
if __name__ == '__main__':
main()
- 打印出来的不是我们想要的结果, 利用正则表达式获取, 最后再利用try…except捕捉异常
# -*- coding: utf-8 -*-
import re
from selenium import webdriver
from selenium.common.exceptions import TimeoutException
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC
browser = webdriver.Chrome()
def get_one_page():
'''获取单个页面'''
try:
browser.get("https://www.xxxxx.com")
input = WebDriverWait(browser,10).until(
EC.presence_of_element_located((By.CSS_SELECTOR,"#q")))
input.send_keys("男装")
button = WebDriverWait(browser,10).until(
EC.element_to_be_clickable((By.CSS_SELECTOR,"#J_TSearchForm > div.search-button > button")))
button.click()
pages = WebDriverWait(browser,10).until(
EC.presence_of_element_located((By.CSS_SELECTOR,"#mainsrp-pager > div > div > div > div.total")))
return pages.text
except TimeoutException:
return get_one_page() #如果超时,继续获取
def main():
pages = get_one_page()
pages = int(re.compile("(\d+)").findall(pages)[0]) #采用正则表达式提取文本中的总页数
print(pages)
if __name__ == '__main__':
main()
关于Selenium的更多内容,可参看官方文档https://selenium-python.readthedocs.io/waits.html
获取多个商品界面
采用获取"到第 页"输入框方式, 切换到下一页, 同样是等待判断
需要注意的是, 最后要加入判断: 高亮是否是当前页
def get_next_page(page):
try:
input = WebDriverWait(browser, 10).until(
EC.presence_of_element_located((By.CSS_SELECTOR, "#mainsrp-pager > div > div > div > div.form > input"))) # 若输入框加载成功,则获取,否则等待
input.send_keys(page) # 输入页码
button = WebDriverWait(browser, 10).until(
EC.element_to_be_clickable((By.CSS_SELECTOR, "#mainsrp-pager > div > div > div > div.form > span.btn.J_Submit"))) # 若按钮可点击,则获取,否则等待
button.click() # 点击按钮
WebDriverWait(browser,10).until(
EC.text_to_be_present_in_element((By.CSS_SELECTOR,"#mainsrp-pager > div > div > div > ul > li.item.active > span"),str(page))) # 判断高亮是否是当前页
except TimeoutException: # 超时, 继续请求
return get_next_page(page)
def main():
pages = get_one_page()
pages = int(re.compile("(\d+)").findall(pages)[0])
for page in range(1,pages+1):
get_next_page(page)
if __name__ == '__main__':
main()
获取商品信息
首先, 判断信息是否加载成功, 紧接着获取源码并初始化, 进而解析.
需要注意的是, 在"get_one_page"和"get_next_page"中调用之后, 才可执行
def get_info():
"""获取详情"""
WebDriverWait(browser,20).until(EC.presence_of_element_located((
By.CSS_SELECTOR,"#mainsrp-itemlist .items .item"))) #判断商品信息是否加载成功
text = browser.page_source #获取网页源码
html = pq(text) #初始化网页源码
items = html('#mainsrp-itemlist .items .item').items() #采用items方法会得到生成器
for item in items: #遍历每个节点对象
data = []
image = item.find(".pic .img").attr("src") #用find方法查找子孙节点,用attr方法获取属性名称
price = item.find(".price").text().strip().replace("\n","") #用text方法获取文本,strip()去掉前后字符串,默认是空格
deal = item.find(".deal-cnt").text()[:-2]
title = item.find(".title").text().strip()
shop = item.find(".shop").text().strip()
location = item.find(".location").text()
data.append([shop, location, title, price, deal, image])
print(data)
保存到MySQL数据库
def save_to_mysql(data):
"""存储到数据库"""
# 创建数据库连接对象
db= pymysql.connect(host = "localhost",user = "root",password = "password",port = 3306, db = "spiders",charset = "utf8")
# 获取游标
cursor = db.cursor()
#创建数据库
cursor.execute("CREATE TABLE IF NOT EXISTS {0}(shop VARCHAR(20),location VARCHAR(10),title VARCHAR(255),price VARCHAR(20),deal VARCHAR(20), image VARCHAR(255))".format("男装"))
#SQL语句
sql = "INSERT INTO {0} values(%s,%s,%s,%s,%s,%s)".format("男装")
try:
#传入参数sql,data
if cursor.execute(sql,data):
#插入数据库
db.commit()
print("********已入库**********")
except:
print("#########入库失败#########")
#回滚,相当什么都没做
db.rollback()
#关闭数据库
db.close()
完整代码
import re
import pymysql
from selenium import webdriver
from selenium.common.exceptions import TimeoutException
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC
from pyquery import PyQuery as pq
'''
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'''
browser = webdriver.Chrome()
def get_one_page(name):
'''获取单个页面'''
print("-----------------------------------------------获取第一页-------------------------------------------------------")
try:
browser.get("https://www.xxxxx.com")
input = WebDriverWait(browser,10).until(
EC.presence_of_element_located((By.CSS_SELECTOR,"#q")))
input.send_keys(name)
button = WebDriverWait(browser,10).until(
EC.element_to_be_clickable((By.CSS_SELECTOR,"#J_TSearchForm > div.search-button > button")))
button.click()
pages = WebDriverWait(browser,10).until(
EC.presence_of_element_located((By.CSS_SELECTOR,"#mainsrp-pager > div > div > div > div.total")))
print("----即将解析第一页信息----")
get_info(name)
print("----第一页信息解析完成----")
return pages.text
except TimeoutException:
return get_one_page(name)
def get_next_page(page,name):
"""获取下一页"""
print("---------------------------------------------------正在获取第{0}页----------------------------------------".format(page))
try:
input = WebDriverWait(browser, 10).until(
EC.presence_of_element_located((By.CSS_SELECTOR, "#mainsrp-pager > div > div > div > div.form > input")))
input.send_keys(page)
button = WebDriverWait(browser, 10).until(
EC.element_to_be_clickable((By.CSS_SELECTOR, "#mainsrp-pager > div > div > div > div.form > span.btn.J_Submit")))
button.click()
WebDriverWait(browser,10).until(
EC.text_to_be_present_in_element((By.CSS_SELECTOR,"#mainsrp-pager > div > div > div > ul > li.item.active > span"),str(page)))
print("-----即将解析第{0}页信息-----".format(page))
get_info(name)
print("-----第{0}页信息解析完成-----".format(page))
except TimeoutException:
return get_next_page(page,name)
def get_info(name):
"""获取详情"""
WebDriverWait(browser,20).until(EC.presence_of_element_located((
By.CSS_SELECTOR,"#mainsrp-itemlist .items .item")))
text = browser.page_source
html = pq(text)
items = html('#mainsrp-itemlist .items .item').items()
for item in items:
data = []
image = item.find(".pic .img").attr("src")
price = item.find(".price").text().strip().replace("\n","")
deal = item.find(".deal-cnt").text()[:-2]
title = item.find(".title").text().strip()
shop = item.find(".shop").text().strip()
location = item.find(".location").text()
data.append([shop, location, title, price, deal, image])
for dt in data:
save_to_mysql(dt,name)
def save_to_mysql(data,name):
"""存储到数据库"""
db= pymysql.connect(host = "localhost",user = "root",password = "password",port = 3306, db = "spiders",charset = "utf8")
cursor = db.cursor()
cursor.execute("CREATE TABLE IF NOT EXISTS {0}(shop VARCHAR(20),location VARCHAR(10),title VARCHAR(255),price VARCHAR(20),deal VARCHAR(20), image VARCHAR(255))".format(name))
sql = "INSERT INTO {0} values(%s,%s,%s,%s,%s,%s)".format(name)
try:
if cursor.execute(sql,data):
db.commit()
print("********已入库**********")
except:
print("#########入库失败#########")
db.rollback()
db.close()
def main(name):
pages = get_one_page(name)
pages = int(re.compile("(\d+)").findall(pages)[0])
for page in range(1,pages+1):
get_next_page(page,name)
if __name__ == '__main__':
name = "男装"
main(name)