属 性

属性:与数据有关的项目,可以是简单的数据值,也可以是可执行对象,比如函数和方法.object.attribute

fileName=raw_input('enter a file name:')
file = open(fileName,'r')
for eachLine in file:
    print eachLine,
file.close()

enter a file name:testFile
test1
test2
test3

enter a file name:aaa
Traceback (most recent call last):
  File "/home/xiangjie/code/Python/test02/openTestFile.py", line 2, in <module>
    file = open(fileName,'r')
IOError: [Errno 2] No such file or directory: 'aaa'

异常是个好东东啊

try:
    fileName=raw_input('enter a file name:')
    file = open(fileName,'r')
    for eachLine in file:
        print eachLine,
    file.close()
except IOError,e:
    print 'file open error:',e

enter a file name:aaa
file open error: [Errno 2] No such file or directory: 'aaa'