爬蟲筆記:Python Selenium詳解
1.簡介
Selenium是一個用於測試網站的自動化測試工具,支援各種瀏覽器包括Chrome、Firefox、Safari等主流介面瀏覽器,同時也支援phantomJS無介面瀏覽器。
支援多種作業系統如Windows、Linux、IOS、Android等。
2.安裝
pip install Selenium
3.安裝瀏覽器驅動
當selenium升級到3.0之後,對不同的瀏覽器驅動進行了規範。如果想使用selenium驅動不同的瀏覽器,必須單獨下載並設定不同的瀏覽器驅動。
各瀏覽器下載地址:
Firefox瀏覽器驅動:https://github.com/mozilla/geckodriver/releases
Chrome瀏覽器驅動:連結1
連結2
IE瀏覽器驅動:http://selenium-release.storage.googleapis.com/index.html
Edge瀏覽器驅動:https://developer.microsoft.com/en-us/microsoft-edge/tools/webdriver/
Opera瀏覽器驅動:https://github.com/operasoftware/operachromiumdriver/releases
PhantomJS瀏覽器驅動:https://phantomjs.org/
1.基本使用
from selenium import webdriver#瀏覽器驅動物件
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
path='D:\chromedriver_win32\chromedriver.exe'#驅動目錄
browser = webdriver.Chrome(path) #宣告一個瀏覽器物件
try:
browser.get('https://www.baidu.com')#訪問網址
input = browser.find_element_by_id('kw')
input.send_keys('Python')#在鍵盤裡輸入python
input.send_keys(Keys.ENTER)#輸入回車
wait = WebDriverWait(browser, 10)#等待10秒
wait.until(EC.presence_of_element_located((By.ID, 'content_left')))#等待ID為content_left加載出來
print(browser.current_url)
print(browser.get_cookies())
print(browser.page_source)#原始碼
finally:
browser.close()
2.宣告瀏覽器物件
from selenium import webdriver
browser = webdriver.Chrome()
browser = webdriver.Firefox()
browser = webdriver.Edge()
browser = webdriver.PhantomJS()
browser = webdriver.Safari()
3.訪問頁面
from selenium import webdriver
path='D:\chromedriver_win32\chromedriver.exe'#驅動目錄
browser = webdriver.Chrome(path)
browser.get('https://www.taobao.com')
print(browser.page_source)#列印原始碼
#browser.close()
瀏覽器會自動開啟淘寶頁面,如果要關閉,可以在末尾新增browser.close()。
瀏覽器淘寶頁面會一閃而過
page_source
查詢元素
4.查詢單個元素
from selenium import webdriver
path='D:\chromedriver_win32\chromedriver.exe'#驅動目錄
browser = webdriver.Chrome(path)
browser.get('https://www.taobao.com')
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()
定位元素方法
通用方法
from selenium import webdriver
from selenium.webdriver.common.by import By
path='D:\chromedriver_win32\chromedriver.exe'#驅動目錄
browser = webdriver.Chrome(path)
browser.get('https://www.taobao.com')
input_first = browser.find_element(By.ID, 'q')#通過id
print(input_first)
browser.close()
5.查詢多個元素
from selenium import webdriver
path='D:\chromedriver_win32\chromedriver.exe'#驅動目錄
browser = webdriver.Chrome(path)
browser.get('https://www.taobao.com')
lis = browser.find_elements_by_css_selector('.service-bd li')
print(lis)
browser.close()
選中的是左側導航欄標籤
通用寫法
from selenium import webdriver
from selenium.webdriver.common.by import By
path='D:\chromedriver_win32\chromedriver.exe'#驅動目錄
browser = webdriver.Chrome(path)
browser.get('https://www.taobao.com')
lis = browser.find_elements(By.CSS_SELECTOR, '.service-bd li')
print(lis)
browser.close()
元素互動操作
6.對獲取的元素呼叫互動方法
from selenium import webdriver
import time
path='D:\chromedriver_win32\chromedriver.exe'#驅動目錄
browser = webdriver.Chrome(path)
browser.get('https://www.taobao.com')
input = browser.find_element_by_id('q')#捕捉輸入框
input.send_keys('iPhone')#在輸入框裡輸入iphone
time.sleep(1)#等待1秒
input.clear()#清除
input.send_keys('iPad')#再次輸入ipad
button = browser.find_element_by_class_name('btn-search')#搜尋按鈕
button.click()#點選按鈕
結果如圖
分析輸入框id為q
點選按鈕的class為btn-search
更多操作:http://selenium-python.readthedocs.io/api.html#module-selenium.webdriver.remote.webelement
互動操作
7.互動動作,將動作附加到動作鏈中序列執行
from selenium import webdriver
from selenium.webdriver import ActionChains
path='D:\chromedriver_win32\chromedriver.exe'#驅動目錄
browser = webdriver.Chrome(path)
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')
target = browser.find_element_by_css_selector('#droppable')
actions = ActionChains(browser)
actions.drag_and_drop(source, target)
actions.perform()
執行JavaScript
from selenium import webdriver
path='D:\chromedriver_win32\chromedriver.exe'#驅動目錄
browser = webdriver.Chrome(path)
browser.get('https://www.zhihu.com/explore')
browser.execute_script('window.scrollTo(0, document.body.scrollHeight)')
browser.execute_script('alert("To Bottom")')
獲取元素資訊
9.獲取屬性
from selenium import webdriver
path='D:\chromedriver_win32\chromedriver.exe'#驅動目錄
from selenium.webdriver import ActionChains
browser = webdriver.Chrome(path)
url = 'https://blog.csdn.net/KOBEYU652453/article/details/113743933'
browser.get(url)
logo = browser.find_element_by_id('article_content')#定位
print(logo)
print(logo.get_attribute('class'))#獲取logo的class
結果
網頁中的class
10.獲取文字值
from selenium import webdriver
path='D:\chromedriver_win32\chromedriver.exe'#驅動目錄
browser = webdriver.Chrome(path)
url = 'https://blog.csdn.net/KOBEYU652453/article/details/113743933'
browser.get(url)
input = browser.find_element_by_class_name('article_content')
print(input.text)
11.獲取ID、位置、標籤名、大小
from selenium import webdriver
path='D:\chromedriver_win32\chromedriver.exe'#驅動目錄
browser = webdriver.Chrome(path)
url = 'https://blog.csdn.net/KOBEYU652453/article/details/113743933'
browser.get(url)
input = browser.find_element_by_class_name('article_content')
print(input.id)
print(input.location)
print(input.tag_name)
print(input.size)
Frame
path='D:\chromedriver_win32\chromedriver.exe'#驅動目錄
import time
from selenium import webdriver
from selenium.common.exceptions import NoSuchElementException
browser = webdriver.Chrome(path)
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
當使用了隱式等待執行測試的時候,如果 WebDriver沒有在 DOM中找到元素,將繼續等待,超出設定時間後則丟擲找不到元素的異常, 換句話說,當查詢元素或元素並沒有立即出現的時候,隱式等待將等待一段時間再查詢 DOM,預設的時間是0
from selenium import webdriver
path='D:\chromedriver_win32\chromedriver.exe'#驅動目錄
browser = webdriver.Chrome(path)
browser.implicitly_wait(10)
browser.get('https://www.zhihu.com/explore')
input = browser.find_element_by_class_name('zu-top-add-question')
print(input)
顯示等待
path='D:\chromedriver_win32\chromedriver.exe'#驅動目錄
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(path)
browser.get('https://www.taobao.com/')
wait = WebDriverWait(browser, 10)
input = wait.until(EC.presence_of_element_located((By.ID, 'q')))#等待條件
button = wait.until(EC.element_to_be_clickable((By.CSS_SELECTOR, '.btn-search')))
print(input, button)
等待條件如下
* title_is 標題是某內容
* title_contains 標題包含某內容
* presence_of_element_located 元素加載出,傳入定位元組,如(By.ID, 'p')
* visibility_of_element_located 元素可見,傳入定位元組
* visibility_of 可見,傳入元素物件
* presence_of_all_elements_located 所有元素加載出
* text_to_be_present_in_element 某個元素文字包含某文字
* text_to_be_present_in_element_value 某個元素值包含某文字
* frame_to_be_available_and_switch_to_it frame載入並切換
* invisibility_of_element_located 元素不可見
* element_to_be_clickable 元素可點選
* staleness_of 判斷一個元素是否仍在DOM,可判斷頁面是否已經重新整理
* element_to_be_selected 元素可選擇,傳元素物件
* element_located_to_be_selected 元素可選擇,傳入定位元組
* element_selection_state_to_be 傳入元素物件以及狀態,相等返回True,否則返回False
* element_located_selection_state_to_be 傳入定位元組以及狀態,相等返回True,否則返回False
* alert_is_present 是否出現Alert
前進後退
import time
from selenium import webdriver
path='D:\chromedriver_win32\chromedriver.exe'#驅動目錄
browser = webdriver.Chrome(path)
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
path='D:\chromedriver_win32\chromedriver.exe'#驅動目錄
browser = webdriver.Chrome(path)
browser.get('https://www.zhihu.com/explore')
print(browser.get_cookies())#列印cookies
browser.add_cookie({'name': 'name', 'domain': 'www.zhihu.com', 'value': 'germey'})#新增cookies
print(browser.get_cookies())
browser.delete_all_cookies()#刪除所有cookies
print(browser.get_cookies())
選項卡管理
import time
from selenium import webdriver
path='D:\chromedriver_win32\chromedriver.exe'#驅動目錄
browser = webdriver.Chrome(path)
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')
異常處理
path='D:\chromedriver_win32\chromedriver.exe'#驅動目錄
from selenium import webdriver
from selenium.common.exceptions import TimeoutException, NoSuchElementException
browser = webdriver.Chrome(path)
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()
詳細文件
http://selenium-python.readthedocs.io/api.html#module-selenium.common.exceptions