python爬蟲基礎08-selenium大全2/8-Chrome Webdriver啓動選項

Selenium筆記（2）Chrome Webdriver啓動選項

本文集連接：https://www.jianshu.com/nb/25338984

 

在Selenium中使用不一樣的Webdriver可能會有不同的方法，有些相同的操做會獲得不同的結果，本文主要介紹的是Chrome()的使用方法。

其餘Webdriver能夠查閱官方文檔。

 

Chrome WebDriver Options

 

簡介

這是一個Chrome的參數對象，在此對象中使用add_argument()方法能夠添加啓動參數，添加完畢後能夠在初始化Webdriver對象時將此Options對象傳入，則能夠實現以特定參數啓動Chrome。

 

例子

from selenium import webdriver
from selenium.webdriver.chrome.options import Options
​
# 實例化一個啓動參數對象
chrome_options = Options()
# 添加啓動參數
chrome_options.add_argument('--window-size=1366,768')
# 將參數對象傳入Chrome，則啓動了一個設置了窗口大小的Chrome
browser = webdriver.Chrome(chrome_options=chrome_options)

 

經常使用的啓動參數

啓動參數	做用
--user-agent=""	設置請求頭的User-Agent
--window-size=1366,768	設置瀏覽器分辨率
--headless	無界面運行
--start-maximized	最大化運行
--incognito	隱身模式
--disable-javascript	禁用javascript
--disable-infobars	禁用瀏覽器正在被自動化程序控制的提示

完整啓動參數能夠到此頁面查看：

https://peter.sh/experiments/chromium-command-line-switches/

禁用圖片加載

Chrome的禁用圖片加載參數設置比較複雜，以下所示：

prefs = {
    'profile.default_content_setting_values' : {
        'images' : 2
   }
}
options.add_experimental_option('prefs',prefs)

禁用瀏覽器彈窗

使用瀏覽器時經常會有彈窗彈出，如下選項能夠禁止彈窗：

prefs = {  
    'profile.default_content_setting_values' : {  
        'notifications' : 2  
     }  
}  
options.add_experimental_option('prefs',prefs) 

 

完整文檔

class selenium.webdriver.chrome.options.Options

Bases: object

Method

• __init__()

• add_argument(argument)

  Adds an argument to the listArgs:Sets the arguments

• add_encoded_extension(extension)

  Adds Base64 encoded string with extension data to a list that will be used to extract it to the ChromeDriverArgs:extension: Base64 encoded string with extension data

• add_experimental_option(name, value)

  Adds an experimental option which is passed to chrome.Args:name: The experimental option name. value: The option value.

• add_extension(extension)

  Adds the path to the extension to a list that will be used to extract it to the ChromeDriverArgs:extension: path to the *.crx file

• set_headless(headless=True)

  Sets the headless argumentArgs:headless: boolean value indicating to set the headless option

• to_capabilities()

  Creates a capabilities with all the options that have been set andreturns a dictionary with everything

Values

• KEY = 'goog:chromeOptions'

• arguments

  Returns a list of arguments needed for the browser

• binary_location

  Returns the location of the binary otherwise an empty string

• debugger_address

  Returns the address of the remote devtools instance

• experimental_options

  Returns a dictionary of experimental options for chrome.

• extensions

  Returns a list of encoded extensions that will be loaded into chrome

• headless

  Returns whether or not the headless argument is set

 

Chrome WebDriver對象

 

簡介

這個對象繼承自selenium.webdriver.remote.webdriver.WebDriver，這個類會在下一章講到，Chrome的WebDriver做爲子類增添了幾個方法。

 

指定chromedriver.exe的位置

chromedriver.exe通常能夠放在環境文件中，可是有時候爲了方便部署項目，或者爲了容易打包，咱們能夠將chromedriver.exe放到咱們的項目目錄中，而後在初始化Chrome Webdriver對象時，傳入chromedriver.exe的路徑。

以下所示：

from selenium import webdriver
browser = webdriver.Chrome(executable_path='chromedriver.exe')

 

完整文檔

class selenium.webdriver.chrome.webdriver.WebDriver(executable_path='chromedriver', port=0, options=None, service_args=None, desired_capabilities=None, service_log_path=None, chrome_options=None)

Bases: selenium.webdriver.remote.webdriver.WebDriver

Controls the ChromeDriver and allows you to drive the browser.

You will need to download the ChromeDriver executable fromhttp://chromedriver.storage.googleapis.com/index.html

• __init__(executable_path='chromedriver', port=0, options=None, service_args=None, desired_capabilities=None, service_log_path=None, chrome_options=None)

  Creates a new instance of the chrome driver.

  Starts the service and then creates new instance of chrome driver.

  Args:

  • executable_path - path to the executable. If the default is used it assumes the executable is in the $PATHport

  • port you would like the service to run, if left as 0, a free port will be found.

  • desired_capabilities: Dictionary object with non-browser specific capabilities only, such as 「proxy」 or 「loggingPref」.

  • options: this takes an instance of ChromeOptions

• create_options()

• get_network_conditions()

  Gets Chrome network emulation settings.

  Returns:A dict. For example:

  {‘latency’: 4, ‘download_throughput’: 2, ‘upload_throughput’: 2, ‘offline’: False}

• launch_app(id)

  Launches Chrome app specified by id.

• quit()

  Closes the browser and shuts down the ChromeDriver executable that is started when starting the ChromeDriver

• set_network_conditions(**network_conditions)

  Sets Chrome network emulation settings.

  Args:

  • network_conditions: A dict with conditions specification.

  Usage:

  driver.set_network_conditions(offline=False, latency=5, # additional latency (ms)
                                download_throughput=500 * 1024, # maximal throughput
                                upload_throughput=500 * 1024) # maximal throughput

   

  Note: ‘throughput’ can be used to set both (for download and upload).