python—selenium

环境安装

"""
# 安装
pip install selenium

# 下载驱动
# 先查询谷歌浏览器的版本号，下载对应的驱动，然后复制到python 执行环境目录下
# http://chromedriver.storage.googleapis.com/index.html
# https://npm.taobao.org

# linux是python对应的bin
# windwos 是D:\Anaconda3\envs\ALL\Scripts
# ALL 是虚拟环境
"""

基本使用

可以先略过，跑通即可，下面我们详细来介绍

from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.common.keys import Keys
from selenium.webdriver.support import expected_conditions as EC
from selenium.webdriver.support.wait import WebDriverWait

browser = webdriver.Chrome()
try:
    browser.get('https://www.baidu.com')
    input = browser.find_element_by_id('kw')
    input.send_keys('Python')
    input.send_keys(Keys.ENTER)
    wait = WebDriverWait(browser, 10)
    wait.until(EC.presence_of_element_located((By.ID, 'content_left')))
    print(browser.current_url)
    print(browser.get_cookies())
    print(browser.page_source)
finally:
    browser.close()

声明浏览器对象

# 引入这个包
from selenium import webdriver
# 声明一个浏览器对象
browser = webdriver.Chrome()
"""
browser = webdriver.Firefox()
browser = webdriver.Edge()
browser = webdriver.PhantomJS()
browser = webdriver.Safari()
"""

访问页面

from selenium import webdriver

browser = webdriver.Chrome()
#访问淘宝
browser.get('https://www.taobao.com')
# 打印网页的源代码
print(browser.page_source)
# 关闭浏览器
browser.close()

查找元素

单个元素

from selenium import webdriver

browser = webdriver.Chrome()
browser.get('https://www.taobao.com')

# 以下三种方法 都是寻找元素的方法，看结果是一样的
input_first = browser.find_element_by_id('q')
input_second = browser.find_element_by_css_selector('#q')
input_third = browser.find_element_by_xpath('//*[@id="q"]')

print(input_first, input_second, input_third)
browser.close()

"""
常用的查找方式
find_element_by_name
find_element_by_xpath
find_element_by_link_text
find_element_by_partial_link_text
find_element_by_tag_name
find_element_by_class_name
find_element_by_css_selector
"""


from selenium import webdriver
from selenium.webdriver.common.by import By

browser = webdriver.Chrome()
browser.get('https://www.taobao.com')
# 这样也是可以的 把by_xxx 当做参数传
input_first = browser.find_element(By.ID, 'q')
print(input_first)
browser.close()

多个元素

from selenium import webdriver

browser = webdriver.Chrome()
browser.get('https://www.taobao.com')
lis = browser.find_elements_by_css_selector('.service-bd li')
print(lis)
browser.close()



from selenium import webdriver
from selenium.webdriver.common.by import By

browser = webdriver.Chrome()
browser.get('https://www.taobao.com')
lis = browser.find_elements(By.CSS_SELECTOR, '.service-bd li')
print(lis)
browser.close()

"""
返回结果都是列表

find_elements_by_name
find_elements_by_xpath
find_elements_by_link_text
find_elements_by_partial_link_text
find_elements_by_tag_name
find_elements_by_class_name
find_elements_by_css_selector
"""

元素的交互操作

获取特定的元素

from selenium import webdriver
import time

browser = webdriver.Chrome()
browser.get('https://www.taobao.com')
input = browser.find_element_by_id('q')
input.send_keys('iPhone') #输入iphone
time.sleep(1)
input.clear() #清空
input.send_keys('iPad') #输入ipad
button = browser.find_element_by_class_name('btn-search') #绑定搜索
button.click() # 点击搜索
# 可能会出现要求登录的情况，先登录  或者用其他办法添加cookie信息
"""
更多操作:
http://selenium-python.readthedocs.io/api.html#module-selenium.webdriver.remote.webelement
"""

交互动作

将动作附加到动作链中串行执行

from selenium import webdriver
from selenium.webdriver import ActionChains

browser = webdriver.Chrome()
# 请求url
url = 'http://www.runoob.com/try/try.php?filename=jqueryui-api-droppable'
browser.get(url)
# 切换 进行拖拽
browser.switch_to.frame('iframeResult')
source = browser.find_element_by_css_selector('#draggable')
target = browser.find_element_by_css_selector('#droppable')
# 声明ActionChains 动作链
actions = ActionChains(browser)	
actions.drag_and_drop(source, target)
# 执行
actions.perform()

"""
更多操作: 
http://selenium-python.readthedocs.io/api.html#module-selenium.webdriver.common.action_chains
"""

执行JavaScript

from selenium import webdriver

browser = webdriver.Chrome()
browser.get('https://www.zhihu.com/explore')
# 执行JS代码execute_script
browser.execute_script('window.scrollTo(0, document.body.scrollHeight)')
browser.execute_script('alert("To Bottom")')

获取元素信息

获取属性

from selenium import webdriver
from selenium.webdriver import ActionChains

browser = webdriver.Chrome()
url = 'https://www.zhihu.com/explore'
browser.get(url)
# 查找id = zh-top-link-logo
logo = browser.find_element_by_id('zh-top-link-logo')
print(logo)
# 打印它的class
print(logo.get_attribute('class'))

获取文本值

from selenium import webdriver

browser = webdriver.Chrome()
url = 'https://www.zhihu.com/explore'
browser.get(url)
input = browser.find_element_by_class_name('zu-top-add-question')
print(input.text)

获取ID、位置、标签名、大小

from selenium import webdriver

browser = webdriver.Chrome()
url = 'https://www.zhihu.com/explore'
browser.get(url)
input = browser.find_element_by_class_name('zu-top-add-question')
print(input.id)
print(input.location)
print(input.tag_name)
print(input.size)
"""
0.6822924344980397-1
{'y': 7, 'x': 774}
button
{'height': 32, 'width': 66}
"""

Frame

import time
from selenium import webdriver
from selenium.common.exceptions import NoSuchElementException

browser = webdriver.Chrome()
url = 'http://www.runoob.com/try/try.php?filename=jqueryui-api-droppable'
browser.get(url)
browser.switch_to.frame('iframeResult')
source = browser.find_element_by_css_selector('#draggable')
print(source)
try:
    logo = browser.find_element_by_class_name('logo')
except NoSuchElementException:
    print('NO LOGO')
browser.switch_to.parent_frame()
logo = browser.find_element_by_class_name('logo')
print(logo)
print(logo.text)

等待

隐式等待

当使用了隐式等待执行测试的时候，如果 WebDriver没有在 DOM中找到元素，将继续等待，超出设定时间后则抛出找不到元素的异常, 换句话说，当查找元素或元素并没有立即出现的时候，隐式等待将等待一段时间再查找 DOM，默认的时间是0

from selenium import webdriver

browser = webdriver.Chrome()
browser.implicitly_wait(10)
browser.get('https://www.zhihu.com/explore')
input = browser.find_element_by_class_name('zu-top-add-question')
print(input)

显示等待

指定一个等待条件和等待时间

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()
browser.get('https://www.taobao.com/')
wait = WebDriverWait(browser, 10)
input = wait.until(EC.presence_of_element_located((By.ID, 'q')))
button = wait.until(EC.element_to_be_clickable((By.CSS_SELECTOR, '.btn-search')))
print(input, button)

"""
一些常见的判断条件


title_is 标题是某内容
title_contains 标题包含某内容
presence_of_element_located 元素加载出，传入定位元组，如(By.ID, 'p')
visibility_of_element_located 元素可见，传入定位元组
visibility_of 可见，传入元素对象
presence_of_all_elements_located 所有元素加载出
text_to_be_present_in_element 某个元素文本包含某文字
text_to_be_present_in_element_value 某个元素值包含某文字
frame_to_be_available_and_switch_to_it frame加载并切换
invisibility_of_element_located 元素不可见
element_to_be_clickable 元素可点击
staleness_of 判断一个元素是否仍在DOM，可判断页面是否已经刷新
element_to_be_selected 元素可选择，传元素对象
element_located_to_be_selected 元素可选择，传入定位元组
element_selection_state_to_be 传入元素对象以及状态，相等返回True，否则返回False
element_located_selection_state_to_be 传入定位元组以及状态，相等返回True，否则返回False
alert_is_present 是否出现Alert

详细内容：
http://selenium-python.readthedocs.io/api.html#module-selenium.webdriver.support.expected_conditions
"""

前进后退

import time
from selenium import webdriver

browser = webdriver.Chrome()
browser.get('https://www.baidu.com/')
browser.get('https://www.taobao.com/')
browser.get('https://www.python.org/')
browser.back()
time.sleep(1)
browser.forward()
browser.close()

Cookies

from selenium import webdriver

browser = webdriver.Chrome()
browser.get('https://www.zhihu.com/explore')
print(browser.get_cookies())
browser.add_cookie({'name': 'name', 'domain': 'www.zhihu.com', 'value': 'germey'})
print(browser.get_cookies())
browser.delete_all_cookies()
print(browser.get_cookies())

选项卡管理

import time
from selenium import webdriver

browser = webdriver.Chrome()
browser.get('https://www.baidu.com')
browser.execute_script('window.open()')
print(browser.window_handles)
browser.switch_to_window(browser.window_handles[1])
browser.get('https://www.taobao.com')
time.sleep(1)
browser.switch_to_window(browser.window_handles[0])
browser.get('https://python.org')

异常处理

from selenium import webdriver

browser = webdriver.Chrome()
browser.get('https://www.baidu.com')
browser.find_element_by_id('hello')

from selenium import webdriver
from selenium.common.exceptions import TimeoutException, NoSuchElementException

browser = webdriver.Chrome()
try:
    browser.get('https://www.baidu.com')
except TimeoutException:
    print('Time Out')
try:
    browser.find_element_by_id('hello')
except NoSuchElementException:
    print('No Element')
finally:
    browser.close()

# 详细文档：

http://selenium-python.readthedocs.io/api.html#module-selenium.common.exceptions