使用循环获取一组元素

Question

每当我在循环中将一个元素附加到一个新列表中时，我都会得到许多重复这些元素的列表。如何获得包含所有元素的单个列表而不重复它们？

n, r = [5, 2]
ans = 0
l = [0]
while n-1>0:
    ans = ans+r
    for i in range(ans):

        if ans not in l:
            l.append(ans)
        print(l)
    n-=1



#I was hoping to get this answer:
 [0,2,4,6,8]
#Instead, I got this:
 [0, 2]
 [0, 2]
 [0, 2, 4]
 [0, 2, 4]
 [0, 2, 4]
 [0, 2, 4]
 [0, 2, 4, 6]
 [0, 2, 4, 6]
 [0, 2, 4, 6]
 [0, 2, 4, 6]
 [0, 2, 4, 6]
 [0, 2, 4, 6]
 [0, 2, 4, 6, 8]
 [0, 2, 4, 6, 8]
 [0, 2, 4, 6, 8]
 [0, 2, 4, 6, 8]
 [0, 2, 4, 6, 8]
 [0, 2, 4, 6, 8]
 [0, 2, 4, 6, 8]
 [0, 2, 4, 6, 8]

Answer 1

在loop之外使用print：

n, r = [5, 2]
ans = 0
l = [0]
while n-1>0:
    ans = ans+r
    for i in range(ans):

        if ans not in l:
            l.append(ans)
    n-=1
print l