启动浏览器一般这么写：
from selenium import webdriver
driver = webdriver.Chrome() # driver = webdriver.Ie() # driver = webdriver.Firefox()
简单写个启动浏览器函数，将已经在本机安装过驱动的浏览器写在函数里：
#coding:utf-8
"""
启动浏览器
"""
from selenium import webdriver
def launch_browser(browsername):
if browsername.lower() == "chrome":
driver = webdriver.Chrome()
elif browsername.lower() == "firefox":
driver = webdriver.Firefox()
elif browsername.lower() == 'ie':
driver = webdriver.Ie()
else:
raise Exception("sorry,该浏览器不在启动范围内，请安装驱动并修改launch_browser函数")
return driver
使用：
driver = launch_browser('chrome') # 启动chrome浏览器
driver = launch_browser('ie') # 启动ie浏览器
driver = launch_browser('firefox') # 启动火狐浏览器
driver = launch_browser('safari') #启动未安装驱动的浏览器
