selenium去掉下载弹窗

from selenium import webdriver
import time
import urllib2

class Download():

    def __init__(self):

        self.fp = webdriver.FirefoxProfile()

        self.fp.set_preference("browser.download.folderList",2)
        self.fp.set_preference("browser.download.manager.showWhenStarting",False)
        self.fp.set_preference("browser.download.dir", r"C:\download")
        self.fp.set_preference("browser.helperApps.neverAsk.saveToDisk",
                          "application/octet-stream")        

    def ClickAndDown(self,baseurl,classname):

        dr = webdriver.Firefox(firefox_profile=self.fp)

        dr.get(baseurl)

        time.sleep(10)

        downbtn = dr.find_element_by_class_name(classname)

        time.sleep(1)

        downbtn.click()

        time.sleep(60)

        dr.close()

        dr.quit()

        dr = None

        time.sleep(10)