定位并登陆QQ空间

try:    
  driver.find_elements_by_id('login')    
a = Trueexcept:    a = False
  if a == True:    
   driver.switch_to.frame('login_frame') 
   driver.find_element_by_id('switcher_plogin').click()  
   driver.find_element_by_id('u').clear() 
   driver.find_element_by_id('u').send_keys(QQ)    
   driver.find_element_by_id('p').clear() 
   driver.find_element_by_id('p').send_keys(key)  
   driver.find_element_by_id('login_button').click()