python+seleliunm ui自动化打开浏览器（firefox报错）

Traceback (most recent call last):
File "", line 4, in <module>
driver = webdriver.Firefox()
File "D:\Python\python\lib\site-packages\selenium\webdriver\firefox\webdriver.py", line 77, in __init__
self.binary, timeout),
File "D:\Python\python\lib\site-packages\selenium\webdriver\firefox\extension_connection.py", line 49, in __init__
self.binary.launch_browser(self.profile)
File "D:\Python\python\lib\site-packages\selenium\webdriver\firefox\firefox_binary.py", line 68, in launch_browser
self._wait_until_connectable()
File "D:\Python\python\lib\site-packages\selenium\webdriver\firefox\firefox_binary.py", line 98, in _wait_until_connectable
raise WebDriverException("The browser appears to have exited "
selenium.common.exceptions.WebDriverException: Message: The browser appears to have exited before we could connect. If you specified a log_file in the FirefoxBinary constructor, check it for details.
Process finished with exit code 1