Python爬虫之用Selenium+PyQuery抓取淘宝美食信息

本次爬虫学习使用了Selenium来模拟浏览器的行为，同时运用了PyQuery抓取相应信息，下面的代码只是简单地打印出来，而没有保存到本地。

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
from pyquery import PyQuery as pq

browser = webdriver.Chrome()
wait = WebDriverWait(browser, 10)

def search():
    try:
        browser.get('https://www.taobao.com')
        input = wait.until(
            EC.presence_of_element_located((By.CSS_SELECTOR, "#q"))
        )
        submit = wait.until(EC.element_to_be_clickable((By.CSS_SELECTOR, "#J_TSearchForm > div.search-button > button"))) #参数为元组类型
        input.send_keys('美食')
        submit.click()
        total = wait.until(EC.presence_of_element_located((By.CSS_SELECTOR, "#mainsrp-pager > div > div > div > div.total")))
        get_products()
        return total.text
    except TimeoutException:
        return search()

def next_page(page_number):
    try:
        input = wait.until(
             EC.presence_of_element_located((By.CSS_SELECTOR, "#mainsrp-pager > div > div > div > div.form > input"))
        )
        submit = wait.until(EC.element_to_be_clickable((By.CSS_SELECTOR, "#mainsrp-pager > div > div > div > div.form > span.btn.J_Submit")))
        input.clear()
        input.send_keys(page_number)
        submit.click()
        wait.until(EC.text_to_be_present_in_element((By.CSS_SELECTOR, "#mainsrp-pager > div > div > div > ul > li.item.active > span"), str(page_number)))
        get_products()
    except TimeoutException:
        next_page(page_number)

def get_products():
    wait.until(EC.presence_of_element_located((By.CSS_SELECTOR, '#mainsrp-itemlist .items .item')))
    html = browser.page_source
    doc = pq(html)
    items = doc('#mainsrp-itemlist .items .item').items()
    for item in items:
        product = {
            'image': item.find('.pic .img').attr('src'),
            'price': item.find('.price').text(),
            'deal': item.find('.deal-cnt').text()[:-3],
            'title': item.find('.title').text(),
            'shop': item.find('.shop').text(),
            'location': item.find('.location').text()
        }
        print(product)

def main():
    try:
        total = search()
        total = int(re.compile('(\d+)').search(total).group(1))
        for i in range(2, total + 1):
            next_page(i)
    except Exception:
        print('Error')
    finally:   
        browser.close()

if __name__ == '__main__':
    main()

当用Selenium模拟浏览器时，可能因为网速等原因，执行代码时，相应的内容还没有加载出来而出现问题，所以用到了WebDriverWait方法。等待的条件有很多，这里主要用到了三种EC.presence_of_element_located，EC.element_to_be_clickable和EC.text_to_be_present_in_element，输入的参数为一个元组。

在CSS中，井号(#)代表id，点号(.)代表class，大于号(>)代表选择直接子代。