首先下载Firebug XPI 文件，然后调用​add_extension​方法：

from selenium import webdriver

fp = webdriver.FirefoxProfile()

fp.add_extension(extension='firebug-1.8.4.xpi')
fp.set_preference("extension.firebug.currentVersion","1.8.4") # Avoid startup screen
browser = webdriver.Firefox(firefox_profile=fp)