day4-去重三种方法

str1 = [12, 13, 14, 12, 16, 17, 18, 16]
print(set(str1))

str2 = []
for i in str1:
    if i not in str2:
        str2.append(i)
print (str2)


str3 = list({}.fromkeys(str1).keys())
print (str3)
;