https://www.cnblogs.com/laowangball/p/8424432.html #原始方法,但是会打乱顺序 mylist = [1,2,2,2,2,3,3,3,4,4,4,4]myset = set(mylist) #myset是另外一个列表,里面的内容是mylist里面的无重复 项 # 收件人去重,并保持原来的收件人顺序mailto = ['cc', 'bbbb', 'afa', 'sss', 'bbbb', 'cc', 'shafa']addr_to = list(se