单选题

执行以下代码的结果是？ def checkit(num): if num in [1,2,3]: return True else: return False for i in filter(checkit,[1,2,1,3,1,4]): print (i)

Question

A.1 2 3

B.1,2,3,4

C.1,2,1,3,1

D.1,2,1,3,1,4