selenium实战演练

利用selenium以及pyquery，爬取当当网图书信息，并且将数据存入文件以及MongoDB数据库中。

配置文件：

key="python"
MONGO_URL='localhost'
MONGO_DB='dangdang'
MONGO_TABLE='book'

dangdang.py

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
from config import *
from selenium.common.exceptions import TimeoutException
from pyquery import PyQuery as pq
import json
import pymongo

driver = webdriver.Chrome() #driver=webdriver.PhantomJS()无界面浏览器
client=pymongo.MongoClient(MONGO_URL)
db=client[MONGO_DB]

def search():
    """
    获取关键字，并且获取一共有多少页码
    :return:
    """
    try:
        driver.get("http://book.dangdang.com")
        input = WebDriverWait(driver, 10).until(
            EC.presence_of_element_located((By.CSS_SELECTOR, "#key_S"))
        )
        button=WebDriverWait(driver, 10).until(
            EC.presence_of_element_located((By.CSS_SELECTOR, "#form_search_new > input.button"))
        )
        input.send_keys(key)
        button.click()
        html=driver.page_source
        doc=pq(html)
        li=doc('div.paging > ul > li:nth-last-child(3)')
        total_num=li.text()
        return total_num
    except TimeoutException:
        return search()

def get_one_page():
    """
    获取每一页的信息
    :return:
    """
    html=driver.page_source
    doc=pq(html)
    items=doc('#search_nature_rg ul li').items()
    for item in items:
        yield {
            'title':item.find('a').attr('title'),
            'src':item.find('a').attr('href'),
            'img':item.find('a img').attr('data-original'),
            'price':item.find('.search_pre_price').text(),
            'discount':item.find('.search_discount').text()
        }

def save_to_file(result):
    """
    将字典对象存入到文件中
    :param result:
    :return:
    """
    with open('dangdang.txt','a',encoding='utf-8') as f:
        f.write(json.dumps(result,ensure_ascii=False)+'\n')
        f.close()

def save_to_mongo(result):
    """
    将字典对象存入到数据库
    :param result:
    :return:
    """
    try:
        if db[MONGO_TABLE].insert(result):
            print('存储成功',result)
    except Exception:
        print('存储失败')

def next_page(num):
    """
    获取下一页
    :param num:
    :return:
    """
    try:

        input = WebDriverWait(driver, 10).until(
            EC.presence_of_element_located((By.CSS_SELECTOR, "#t__cp"))
        )

        button=WebDriverWait(driver, 10).until(
            EC.presence_of_element_located((By.CSS_SELECTOR, "#click_get_page"))
        )
        input.clear()
        input.send_keys(num)
        button.click()

    except TimeoutException:
        return next_page(num)

def main():
    total_num=int(search())
    for i in range(2,total_num+1):
        next_page(i)
        results=get_one_page()
        for result in results:
            save_to_file(result)
            save_to_mongo(result)

if __name__ == "__main__":
    main()

存入到文件中的数据：

{"img": null, "src": "http://product.dangdang.com/25228733.html", "price": "¥109.00", "title": " Python数据科学手册", "discount": "定价： (9.6折)"}
{"img": "http://img3m2.ddimg.cn/63/7/25173882-1_b_3.jpg", "src": "http://product.dangdang.com/25173882.html", "price": "¥69.00", "title": " Python游戏编程快速上手 第4版", "discount": "定价： (9.6折)"}
{"img": "http://img3m7.ddimg.cn/75/5/25232007-1_b_3.jpg", "src": "http://product.dangdang.com/25232007.html", "price": "¥79.00", "title": " Python机器学习基础教程", "discount": "定价： (9.6折)"}
{"img": "http://img3m5.ddimg.cn/8/8/25307675-1_b_2.jpg", "src": "http://product.dangdang.com/25307675.html", "price": "¥59.00", "title": " 深度学习入门 基于Python的理论与实现", "discount": "定价： (9.6折)"}
{"img": "http://img3m6.ddimg.cn/10/10/25098886-1_b_2.jpg", "src": "http://product.dangdang.com/25098886.html", "price": "¥79.00", "title": " Python高性能编程", "discount": "定价： (9.6折)"}
{"img": "http://img3m7.ddimg.cn/32/32/27857147-1_b_1.jpg", "src": "http://product.dangdang.com/27857147.html", "price": "¥69.00", "title": " Python深度学习实战：基于TensorFlow和Keras的聊天机器人以及人脸、物体和语音识别", "discount": "定价： (9.6折)"}
{"img": "http://img3m3.ddimg.cn/85/16/25060153-1_b_2.jpg", "src": "http://product.dangdang.com/25060153.html", "price": "¥69.00", "title": " Python极客项目编程", "discount": "定价： (9.6折)"}
{"img": "http://img3m7.ddimg.cn/96/32/26475567-1_b_2.jpg", "src": "http://product.dangdang.com/26475567.html", "price": "¥69.00", "title": " 小小的Python编程故事", "discount": "定价： (9.6折)"}
{"img": "http://img3m6.ddimg.cn/32/4/25339676-1_b_2.jpg", "src": "http://product.dangdang.com/25339676.html", "price": "¥59.00", "title": " Python数据可视化之matplotlib实践", "discount": "定价： (9.6折)"}
{"img": "http://img3m1.ddimg.cn/9/0/25107201-1_b_3.jpg", "src": "http://product.dangdang.com/25107201.html", "price": "¥69.00", "title": " Python与机器学习实战：决策树、集成学习、支持向量机与神经网络算法详解及编程实现", "discount": "定价： (9.6折)"}
{"img": "http://img3m7.ddimg.cn/35/32/25240877-1_b_2.jpg", "src": "http://product.dangdang.com/25240877.html", "price": "¥69.00", "title": " Python数据分析从入门到精通", "discount": "定价： (9.6折)"}
{"img": "http://img3m2.ddimg.cn/15/23/27866832-1_b_3.jpg", "src": "http://product.dangdang.com/27866832.html", "price": "¥69.00", "title": " Python自动化开发实战", "discount": "定价： (8.8折)"}
{"img": "http://img3m6.ddimg.cn/78/36/26485746-1_b_2.jpg", "src": "http://product.dangdang.com/26485746.html", "price": "¥79.00", "title": " Python量化交易实战", "discount": "定价： (8.8折)"}
{"img": "http://img3m5.ddimg.cn/82/2/25218055-1_b_3.jpg", "src": "http://product.dangdang.com/25218055.html", "price": "¥89.00", "title": " Python 3学习笔记（上卷）", "discount": "定价： (9.6折)"}
{"img": "http://img3m4.ddimg.cn/31/7/25219984-1_b_1.jpg", "src": "http://product.dangdang.com/25219984.html", "price": "¥69.00", "title": " Python贝叶斯分析", "discount": "定价： (9.6折)"}
{"img": "http://img3m5.ddimg.cn/43/0/23617285-1_b_1.jpg", "src": "http://product.dangdang.com/23617285.html", "price": "¥38.00", "title": " Python袖珍指南（第五版）", "discount": "定价： (6.9折)"}
{"img": "http://img3m9.ddimg.cn/76/20/24104299-1_b_12.jpg", "src": "http://product.dangdang.com/24104299.html", "price": "¥49.50", "title": " 零基础入门学习Python", "discount": "定价： (8.81折)"}
{"img": "http://img3m7.ddimg.cn/8/12/26913257-1_b_2.jpg", "src": "http://product.dangdang.com/26913257.html", "price": "¥139.00", "title": " Python经典实例", "discount": "定价： (9.6折)"}
{"img": "http://img3m8.ddimg.cn/57/19/25113288-1_b_2.jpg", "src": "http://product.dangdang.com/25113288.html", "price": "¥39.00", "title": " Python设计模式 第2版", "discount": "定价： (9.59折)"}
{"img": "http://img3m8.ddimg.cn/32/34/25253348-1_b_3.jpg", "src": "http://product.dangdang.com/25253348.html", "price": "¥49.00", "title": " Python 3爬虫、数据清洗与可视化实战", "discount": "定价： (9.6折)"}
{"img": "http://img3m8.ddimg.cn/12/34/27859998-1_b_3.jpg", "src": "http://product.dangdang.com/27859998.html", "price": "¥88.00", "title": " Python程序设计", "discount": "定价： (9.61折)"}
{"img": "http://img3m9.ddimg.cn/15/19/24220959-1_b_3.jpg", "src": "http://product.dangdang.com/24220959.html", "price": "¥59.00", "title": " 跟老齐学Python：轻松入门", "discount": "定价： (9.6折)"}
{"img": "http://img3m0.ddimg.cn/39/27/25216230-1_b_6.jpg", "src": "http://product.dangdang.com/25216230.html", "price": "¥128.00", "title": " Head First Python(第二版)", "discount": "定价： (6.9折)"}

存入到MongoDB中：