怎么去除输出的最后一个空格

a=eval(input())
s=[]
d=0
for i in a:
if i not in s:
s.insert(d,i)
d+=1
for i in s:
print(i,end=' ')

a=input()
s=[]
d=0
for i in a:
if i not in s:
s.insert(d,i)
d+=1
for i in range(d-1):
print(s[i],end=' ')
print(s[d-1])