#!/usr/bin/python

aaa=input()

print("the  file is ", aaa)

f = open('aaa')

iter_f = iter(f)

lines=0

for line in iter_f:

    lines += 1

print("is", lines)

运行结果报错：
[root@host36 ~]# python test.py
1.txt
Traceback (most recent call last):
  File "test.py", line 2, in <module>
    aaa=input()
  File "<string>", line 1
    1.txt
       ^
SyntaxError: unexpected EOF while parsing
[root@host36 ~]#