做网站程序看什么书百度如何精准搜索

目录

一、cookie和session实现登录原理

二、模拟登录方法-Requests模块Cookie实现登录

三、cookie+session实现登录并获取数据

四、selenium使用基本代码

五、scrapy+selenium实现登录

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一、cookie和session实现登录原理

cookie:1.网站持久保存在浏览器中的数据2.可以是长期永久或者限时过期

session:1.保存在服务器中的一种映射关系2.在客户端以Cookie形式储存Session_ID

二、模拟登录方法-Requests模块Cookie实现登录

import requestsurl = 'http://my.cheshi.com/user/'headers = {"User-Agent":"Mxxxxxxxxxxxxxxxxxxxxxx"
}
cookies = "pv_uid=16xxxxx;cheshi_UUID=01xxxxxxxxx;cheshi_pro_city=xxxxxxxxxxx"
cookies = {item.split("=")[0]:item.split("=")[1] for item in cookies.split(";")}
cookies = requests.utils.cookiejar_from_dict(cookies)
res = requests.get(url, headers=headers, cookies=cookies)with open("./CO8L02.html","w") as f:f.write(res.text)

三、cookie+session实现登录并获取数据

如下两种方法：

import requestsurl = "https://api.cheshi.com/services/common/api.php?api=login.Login"
headers = {"User-Agent":"Mxxxxxxxxxxxxx"
}
data = {"act":"login","xxxx":"xxxx"........
}
res = requests.post(url, headers=headers, data=data)
print(res.cookies)admin_url = "http://my.cheshi.com/user/"
admin_res = requests.get(admin_url, headers=headers, cookies=res.cookies)with open("./C08L03.html","w") as f：f.write(admin_res.text)

import requestsurl = "https://api.cheshi.com/services/common/api.php?api=login.Login"
headers = {"User-Agent":"Mxxxxxxxxxxxxx"
}
data = {"act":"login","xxxx":"xxxx"........
}
session = requests.session()
session.post(url, headers=headers, data=data)admin_url = "http://my.cheshi.com/user/"
admin_res = session.get(admin_url, headers=headers)
with open("./C08L03b.html","w") as f：f.write(admin_res.text)

四、selenium使用基本代码

from selenium import webdriver
from selenium.webdriver.chrome.service import Service
from selenium.webdriver.common.by import By
# 实现交互的方法
from selenium.webdriver import ActionChains
import timeservice = Service(executable_path="../_resources/chromedriver")
driver = webdriver.Chrome(service=service)
driver.get("http://www.cheshi.com/")# print(drive.page_source)
# print(driver.current_url)
# with open("./C08L05.html", "w") as f:
#     f.write(drive.page_source)# # 屏幕截图
# driver.save_screenshot("C08L05.png")"""元素定位方法."""
# 注意：不要在xpath里面写text()会报错
h1 = driver.find_element(By.XPATH, "//h1")
h1_text = h1.text# 虽然是//p 但是text后只能拿到第一个元素,若拿所有元素需要用find_elements后循环遍历
#items = driver.find_element(By.XPATH, "//p")
# print(items.text)items = driver.find_elements(By.XPATH, "//p")
print(items.text)
for item in items:print(item.text)p = driver.find_element(By.XPATH, '//p[@id="primary"]')
print(p.text)
print(p.get_attribute("another-attr"))# 为了防止报错，可以用try,except方法防止中断程序"""元素交互方法."""
username = driver.find_element(By.XPATH, '//*[@id="username"]')
password = driver.find_element(By.XPATH, '//*[@id="password"]')ActionChains(driver).click(username).pause(1).send_keys("abcde").pause(0.5).perform()
ActionChains(driver).click(password).pause(1).send_keys("12345").pause(0.5).perform()
time.sleep(1)div = driver.find_element(By.XPATH, '//*[@id="toHover"]')
ActionChains(driver).pause(0.5).move_to_element("div").pause(2).perform()
time.sleep(1)div = driver.find_element(By.XPATH, '//*[@id="end"]')
ActionChains(driver).scroll_to_element("div").pause(2).perform()
time.sleep(1)
ActionChains(driver).scroll_by_amount(0,200).perform()
time.sleep(1)time.sleep(2)
driver.quit()

五、scrapy+selenium实现登录

在scrapy中的爬虫文件（app.py)中修改如下代码(两种方法）:

import scrapyclass AppSpider(scrapy.Spider):name = "app"# allowed_domains = ["my.cheshi.com"]# start_urls = ["http://my.cheshi.com/user/"]def start_requests(self):url = "http://my.cheshi.com/user/"cookies = "pv_uid=16xxxxx;cheshi_UUID=01xxxxxxxxx;cheshi_pro_city=xxxxxxxxxxx"cookies = {item.split("=")[0]:item.split("=")[1] for item in cookies.split(";")}yield scrapy.Request(url=url, callback=self.parse,cookies=cookies)def parse(self,response):print(response.text)

import scrapyclass AppSpider(scrapy.Spider):name = "app"# allowed_domains = ["my.cheshi.com"]# start_urls = ["http://my.cheshi.com/user/"]def start_requests(self):url = "https://api.cheshi.com/services/common/api.php?api=login.Login"data = {"act":"login","xxxx":"xxxx"........}yield scrapy.FormRequest(url=url, formdata=data,callback=self.parse)def parse(self,response):url = "http://my.cheshi.com/user/"yield scrapy.Request(url=url, callback=self.parse_admin)def parse_admin(self, response)：print(response.text)