NameError: name 'FileNotFoundError' is not defined的解决方案

处理文件不存在使用FileNotFoundError来处理异常

python版本：2.7

python代码：

filename='waiwai.txt'
try:
	with open(filename) as f_obj:
		contents=f_obj.read()
except FileNotFoundError:
	print "Sorry,the file does't exist."

运行结果：

Traceback (most recent call last):
  File "J:/Python/821_03.py", line 5, in 
    except FileNotFoundError:
NameError: name 'FileNotFoundError' is not defined

Process finished with exit code 1

报错原因：

FileNotFoundError为python3使用的文本不存在异常处理方法

在python2.7中使用IOError

修改后的python代码

filename='waiwai.txt'
try:
	with open(filename) as f_obj:
		contents=f_obj.read()
except IOError:
	print "Sorry,the file does't exist."

运行结果：

Sorry,the file does't exist.

Process finished with exit code 0