爬虫实现翻页功能
from selenium import webdriver
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC
from selenium.webdriver.common.by import By
from selenium.webdriver.common.keys import Keys
import time
import json
import csv
import random
# 声明一个谷歌驱动器，并设置不加载图片，间接加快访问速度
options = webdriver.ChromeOptions()
options.add_experimental_option('prefs', {'profile.managed_default_content_settings.images': 2})
browser = webdriver.Chrome(options=options)
# url
url = 'https://www.jd.com/'
# 声明一个list，存储dict
data_list = []
def start_spider():
# 请求url
browser.get(url)
# 获取输入框的id，并输入关键字python爬虫
browser.find_element_by_id('key').send_keys('python爬虫')
# 输入回车进行搜索
browser.find_element_by_id('key').send_keys(Keys.ENTER)
# 显示等待下一页的元素加载完成
WebDriverWait(browser, 1000).until(
EC.presence_of_all_elements_located(
(By.CLASS_NAME, 'pn-next')
)
)
# 先获取一个有多少页
all_page = eval(browser.find_element_by_css_selector('span.p-skip em b').text)
print(all_page)
# 设置一个计数器
count = 0
# 无限循环
while True:
try:
count += 1
# 显示等待商品信息加载完成
WebDriverWait(browser, 1000).until(
EC.presence_of_all_elements_located(
(By.CLASS_NAME, 'gl-item')
)
)
# 将滚动条拉到最下面的位置，因为往下拉才能将这一页的商品信息全部加载出来
browser.execute_script('document.documentElement.scrollTop=10000')
# 随机延迟,等下元素全部刷新
time.sleep(random.randint(1, 3))
browser.execute_script('document.documentElement.scrollTop=0')
# 开始提取信息,找到ul标签下的全部li标签
lis = browser.find_elements_by_class_name('gl-item')
# 遍历
for li in lis:
# 名字
name = li.find_element_by_xpath('.//div[@class="p-name p-name-type-2"]//em').text
# 价格
price = li.find_element_by_xpath('.//div[@class="p-price"]//i').text
# 评论数
comment = li.find_elements_by_xpath('.//div[@class="p-commit"]//a')
if comment:
comment = comment[0].text
else:
comment = None
# 商铺名字
shop_name = li.find_elements_by_class_name('J_im_icon')
if shop_name:
shop_name = shop_name[0].text
else:
shop_name = None
# 商家类型
shop_type = li.find_elements_by_class_name('goods-icons')
if shop_type:
shop_type = shop_type[0].text
else:
shop_type = None
# 声明一个字典存储数据
data_dict = {}
data_dict['name'] = name
data_dict['price'] = price
data_dict['comment'] = comment
data_dict['shop_name'] = shop_name
data_dict['shop_type'] = shop_type
data_list.append(data_dict)
print(data_dict)
except Exception as e:
continue
# 如果count==all_page就退出循环
if count == all_page:
break
# 找到下一页的元素pn-next
fp_next = browser.find_element_by_xpath('//*[@id = "J_bottomPage"]/span[1]/a[9]/em')
#fp_next = browser.find_element_by_css_selector('a.fp-next')
# 点击下一页
fp_next.click()
def main():
start_spider()
# 将数据写入jsonwenj
# with open('data_json.json', 'a+', encoding='utf-8') as f:
# json.dump(data_list, f, ensure_ascii=False, indent=4)
# print('json文件写入完成')
#
# with open('data_csv.csv', 'w', encoding='utf-8', newline='') as f:
# # 表头
# title = data_list[0].keys()
# # 声明writer
# writer = csv.DictWriter(f, title)
# # 写入表头
# writer.writeheader()
# # 批量写入数据
# writer.writerows(data_list)
# print('csv文件写入完成')
if __name__ == '__main__':
main()
# 退出浏览器
browser.quit()
