Selenium Remote WebDriver中Firefox Profile配置报错：无法JSON序列化

尝试在Docker容器（selenium/standalone-firefox）中配置Firefox Profile运行Selenium测试，但无法整合capabilities、profile和options到Remote WebDriver。引入Profile相关设置时，持续出现如下报错：

^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Program Files\WindowsApps\PythonSoftwareFoundation.Python.3.11_3.11.1008.0_x64__qbz5n2kfra8p0\Lib\json\__init__.py", line 231, in dumps
    return _default_encoder.encode(obj)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Program Files\WindowsApps\PythonSoftwareFoundation.Python.3.11_3.11.1008.0_x64__qbz5n2kfra8p0\Lib\json\encoder.py", line 200, in encode
    chunks = self.iterencode(o, _one_shot=True)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Program Files\WindowsApps\PythonSoftwareFoundation.Python.3.11_3.11.1008.0_x64__qbz5n2kfra8p0\Lib\json\encoder.py", line 258, in iterencode
    return _iterencode(o, 0)
           ^^^^^^^^^^^^^^^^^
  File "C:\Program Files\WindowsApps\PythonSoftwareFoundation.Python.3.11_3.11.1008.0_x64__qbz5n2kfra8p0\Lib\json\encoder.py", line 180, in default
    raise TypeError(f'Object of type {o.__class__.__name__} '
TypeError: Object of type FirefoxProfile is not JSON serializable

以下是我的代码：

from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.common.keys import Keys
from time import sleep
from selenium.webdriver.firefox.options import Options
from selenium.webdriver.firefox.firefox_profile import FirefoxProfile

capabilities = webdriver.DesiredCapabilities.FIREFOX.copy()
capabilities['acceptInsecureCerts'] = True
capabilities['marionette'] = True

profile = webdriver.FirefoxProfile()
profile.set_preference("accept_untrusted_certs", True)
profile.set_preference("browser.download.panel.shown", False)
profile.set_preference("browser.helperApps.neverAsk.openFile","text/csv,application/vnd.ms-excel")
profile.set_preference("browser.helperApps.neverAsk.saveToDisk", "application/msword, application/csv, application/ris, text/csv, image/png, application/pdf, text/html, text/plain, application/zip, application/x-zip, application/x-zip-compressed, application/download, application/octet-stream")
profile.set_preference("browser.download.manager.showWhenStarting", False)
profile.set_preference("browser.download.manager.alertOnEXEOpen", False)
profile.set_preference("browser.download.manager.focusWhenStarting", False)
profile.set_preference("browser.download.folderList", 2)
profile.set_preference("browser.download.useDownloadDir", True)
profile.set_preference("browser.helperApps.alwaysAsk.force", False)
profile.set_preference("browser.download.manager.alertOnEXEOpen", False)
profile.set_preference("browser.download.manager.closeWhenDone", True)
profile.set_preference("browser.download.manager.showAlertOnComplete", False)
profile.set_preference("browser.download.manager.useWindow", False)
profile.set_preference("services.sync.prefs.sync.browser.download.manager.showWhenStarting", False)
profile.set_preference("pdfjs.disabled", True)
profile.set_preference("javascript.enabled", False)
profile.update_preferences()

options=Options()
options.set_preference('profile', profile)
options.set_preference('network.proxy.type', 1)
options.set_preference('network.proxy.socks', '127.0.0.1')
options.set_preference('network.proxy.socks_port', 9050)
options.set_preference('network.proxy.socks_remote_dns', False)

driver = webdriver.Remote(
    command_executor="http://localhost:4444",
    desired_capabilities=capabilities,
    options=options
)

driver.get("https://www.google.com")

search_input_box = driver.find_element(By.NAME, "q")

search_input_box.send_keys("selenium webdriver" + Keys.ENTER)

sleep(60)

driver.quit()

移除Profile或Options设置后可正常运行，但希望能自定义配置，请问问题出在哪里？

问题根源 #

你直接将FirefoxProfile对象通过options.set_preference('profile', profile)传给了Options，但RemoteWebDriver需要把配置序列化成JSON格式传输给Docker中的Selenium节点，而FirefoxProfile对象本身无法被JSON序列化，这就是报错的直接原因。

解决方法（推荐：直接用Options管理所有偏好） #

不需要单独创建FirefoxProfile对象，把所有Profile中的偏好设置直接通过Options.set_preference()来配置，这样所有参数都是可序列化的键值对，能正常传递给Remote节点。

修改后的代码如下：

from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.common.keys import Keys
from time import sleep
from selenium.webdriver.firefox.options import Options

capabilities = webdriver.DesiredCapabilities.FIREFOX.copy()
capabilities['acceptInsecureCerts'] = True
capabilities['marionette'] = True

options=Options()
# 原Profile中的所有偏好直接通过Options设置
options.set_preference("accept_untrusted_certs", True)
options.set_preference("browser.download.panel.shown", False)
options.set_preference("browser.helperApps.neverAsk.openFile","text/csv,application/vnd.ms-excel")
options.set_preference("browser.helperApps.neverAsk.saveToDisk", "application/msword, application/csv, application/ris, text/csv, image/png, application/pdf, text/html, text/plain, application/zip, application/x-zip, application/x-zip-compressed, application/download, application/octet-stream")
options.set_preference("browser.download.manager.showWhenStarting", False)
options.set_preference("browser.download.manager.alertOnEXEOpen", False)
options.set_preference("browser.download.manager.focusWhenStarting", False)
options.set_preference("browser.download.folderList", 2)
options.set_preference("browser.download.useDownloadDir", True)
options.set_preference("browser.helperApps.alwaysAsk.force", False)
options.set_preference("browser.download.manager.closeWhenDone", True)
options.set_preference("browser.download.manager.showAlertOnComplete", False)
options.set_preference("browser.download.manager.useWindow", False)
options.set_preference("services.sync.prefs.sync.browser.download.manager.showWhenStarting", False)
options.set_preference("pdfjs.disabled", True)
options.set_preference("javascript.enabled", False)
# 原代理设置保留
options.set_preference('network.proxy.type', 1)
options.set_preference('network.proxy.socks', '127.0.0.1')
options.set_preference('network.proxy.socks_port', 9050)
options.set_preference('network.proxy.socks_remote_dns', False)

driver = webdriver.Remote(
    command_executor="http://localhost:4444",
    desired_capabilities=capabilities,
    options=options
)

driver.get("https://www.google.com")

search_input_box = driver.find_element(By.NAME, "q")
search_input_box.send_keys("selenium webdriver" + Keys.ENTER)

sleep(60)
driver.quit()

备选方法（适合复杂Profile场景） #

如果必须使用FirefoxProfile对象，可以将其导出为ZIP文件，然后通过options.add_argument()指定--profile参数指向该ZIP路径。注意：Docker环境下需要确保该ZIP文件能被容器访问（比如通过挂载本地目录到容器）。

示例代码片段：

profile = webdriver.FirefoxProfile()
# 配置Profile偏好...
profile.update_preferences()
# 导出为ZIP文件
profile_path = profile.path
import shutil
zip_path = "firefox_profile.zip"
shutil.make_archive(zip_path.replace('.zip', ''), 'zip', profile_path)

options=Options()
# 指定Profile ZIP路径（Docker中需对应挂载路径）
options.add_argument(f'--profile={zip_path}')
# 其他代理设置...

内容的提问来源于stack exchange，提问作者Mr. E