How to use chrome webdriver in selenium to downloa

2020-01-30 08:14发布

Based on the posts here and here I am trying to use a chrome webdriver in selenium to be able to download a file. Here is the code so far

from selenium import webdriver
from selenium.webdriver.chrome.options import Options

chrome_options = Options()
chrome_options.add_argument("--disable-extensions")
chrome_options.add_experimental_option("profile.default_content_settings.popups", 0)
chrome_options.add_experimental_option("download.prompt_for_download", "false")
chrome_options.add_experimental_option("download.default_directory", "/tmp")

driver = webdriver.Chrome(chrome_options=chrome_options)

But this alone results in the following error:

WebDriverException: Message: unknown error: cannot parse capability: chromeOptions
from unknown error: unrecognized chrome option: download.default_directory
  (Driver info: chromedriver=2.24.417424 (c5c5ea873213ee72e3d0929b47482681555340c3),platform=Linux 4.10.0-37-generic x86_64)

So how to fix this? Do I have to use this 'capability' thing? If so, how exactly?

5条回答
家丑人穷心不美
2楼-- · 2020-01-30 08:24

for chrome in mac os, the download.defaultdirectory did not work for me and fortunately savefile.default_directory works.

prefs = {
    "printing.print_preview_sticky_settings.appState": json.dumps(settings),
    "savefile.default_directory": "/Users/creative/python-apps",
    "download.prompt_for_download": False,
    "download.directory_upgrade": True,
    "download.safebrowsing.enabled": True
}
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We Are One
3楼-- · 2020-01-30 08:29

Some tips:

  1. chromium and chromedriver should have same version.

    Typically chromium package should have chromedriver inside, you can find it in the install dir. If you are using ubuntu/debian, execute dpkg -L chromium-chromedriver.

  2. Have a correct Chrome preference config.

    as Satish said, use options.add_experimental_option("prefs", ...) to config selenium+chrome. But sometimes the config may change by time. The beset way to get newest and workable prefs is to check it in the chromium config dir. For example,

    • Launch a chromium in Xorg desktop
    • Change settings in menu
    • Quit chromium
    • Find out the real settings in ~/.config/chromium/Default/Preferences
    • Read it, pick out the exact options you need.

In my case, the code is:

from selenium import webdriver
from selenium.webdriver.common.desired_capabilities import DesiredCapabilities

options = webdriver.ChromeOptions()
options.gpu = False
options.headless = True
options.add_experimental_option("prefs", {
    "download.default_directory" : "/data/books/chrome/",
    'profile.default_content_setting_values.automatic_downloads': 2,
    })

desired = options.to_capabilities()
desired['loggingPrefs'] = { 'performance': 'ALL'}
driver = webdriver.Chrome(desired_capabilities=desired)
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一夜七次
4楼-- · 2020-01-30 08:43

I think that the easiest way to save arbitrary file (i.e. image) using WebDriver is to execute JavaScript which will save file. No configuration required at all!

I use this library FileSaver.js to save a file with desired name with ease.

from selenium import webdriver
import requests

FILE_SAVER_MIN_JS_URL = "https://raw.githubusercontent.com/eligrey/FileSaver.js/master/dist/FileSaver.min.js"

file_saver_min_js = requests.get(FILE_SAVER_MIN_JS_URL).content

chrome_options = webdriver.ChromeOptions()
driver = webdriver.Chrome('/usr/local/bin/chromedriver', options=chrome_options)

# Execute FileSaver.js in page's context
driver.execute_script(file_saver_min_js)

# Now you can use saveAs() function
download_script = f'''
    return fetch('https://cdn.sstatic.net/Sites/stackoverflow/company/img/logos/so/so-logo.svg?v=a010291124bf',
        {{
            "credentials": "same-origin",
            "headers": {{"accept":"image/webp,image/apng,image/*,*/*;q=0.8","accept-language":"en-US,en;q=0.9"}},
            "referrerPolicy": "no-referrer-when-downgrade",
            "body": null,
            "method": "GET",
            "mode": "cors"
        }}
    ).then(resp => {{
        return resp.blob();
    }}).then(blob => {{
        saveAs(blob, 'stackoverflow_logo.svg');
    }});
    '''

driver.execute_script(download_script)
# Done! Your browser has saved an SVG image!
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欢心
5楼-- · 2020-01-30 08:44

From your exception, you are using chromedriver=2.24.417424.

What are the versions of Selenium and Chrome browser that are you using?

I tried the following code with:

  • Selenium 3.6.0
  • chromedriver 2.33
  • Google Chrome 62.0.3202.62 (Official Build) (64-bit)

And it works:

from selenium import webdriver

download_dir = "/pathToDownloadDir"
chrome_options = webdriver.ChromeOptions()
preferences = {"download.default_directory": download_dir ,
               "directory_upgrade": True,
               "safebrowsing.enabled": True }
chrome_options.add_experimental_option("prefs", preferences)
driver = webdriver.Chrome(chrome_options=chrome_options,executable_path=r'/pathTo/chromedriver')

driver.get("urlFileToDownload");

Make sure you are using a browser that is supported by your chromedriver (from here, should be Chrome v52-54).

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可以哭但决不认输i
6楼-- · 2020-01-30 08:45

Try this. Executed on windows

(How to control the download of files with Selenium Python bindings in Chrome)

from selenium import webdriver
from selenium.webdriver.chrome.options import Options

options = Options()
options.add_experimental_option("prefs", {
  "download.default_directory": r"C:\Users\xxx\downloads\Test",
  "download.prompt_for_download": False,
  "download.directory_upgrade": True,
  "safebrowsing.enabled": True
})
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