python在用selenium调Firefox时报错:

Traceback (most recent call last):
  File "G:\python_work\chapter11\test_selenium_firefox.py", line 10, in <module>
    driver = webdriver.Firefox()
  File "C:\Python34\lib\site-packages\selenium\webdriver\firefox\webdriver.py", line 154, in __init__
    keep_alive=True)
  File "C:\Python34\lib\site-packages\selenium\webdriver\remote\webdriver.py", line 140, in __init__
    self.start_session(desired_capabilities, browser_profile)
  File "C:\Python34\lib\site-packages\selenium\webdriver\remote\webdriver.py", line 229, in start_session
    response = self.execute(Command.NEW_SESSION, parameters)
  File "C:\Python34\lib\site-packages\selenium\webdriver\remote\webdriver.py", line 297, in execute
    self.error_handler.check_response(response)
  File "C:\Python34\lib\site-packages\selenium\webdriver\remote\errorhandler.py", line 194, in check_response
    raise exception_class(message, screen, stacktrace)
selenium.common.exceptions.WebDriverException: Message: Unable to find a matching set of capabilities

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python版本3.4.3 , selenium版本3.4.3 , Firefox版本49.0.

报错的原因是python, selenium, Firefox之间的版本兼容问题 , 将Firefox升级到最新版55.0后问题解决.

同时selenium在调用Firefox时需要geckodriver , 下载后添加到Firefox安装目录, 同时添加Firefox安装目录到系统环境变量Path.

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测试代码:

 from selenium import webdriver

 driver = webdriver.Firefox()

 driver.get("http://www.baidu.com")