#方式一
l1 = [1, 2, 333, 7, 1, 8, 19, 1, 2, 333]
res = list(set(l1))
res.sort(key=l1.index)
print(res)
#方式2
l1 = [1, 2, 333, 7, 1, 8, 19, 1, 2, 333]
res = []
for i in l1:
if i not in res:
res.append(i)
print(res)
#方式三
l1 = [1, 2, 333, 7, 1, 8, 19, 1, 2, 333]
s = set(l1)
res = []
for i in l1:
if i in s:
res.append(i)
s.remove(i)
print(res)