try...catch...else...finally f.close 报错
try:
f = open('2.txt')
line = f.read(2)
num = int(line)
print 'read num = %d' %num
except IOError,e:
print 'catch IOError,[%s]' % e
except ValurError,e:
print 'catch ValueError,[%s]' % e
else: #当try模块执行完毕，且无任何异常时，进入else模块
print 'No Error'
finally:
print 'enter finally.close file'
f.close()
为什么pycharm编译器上运行这段代码，会提示finally中的f没有定义呢？：
Traceback (most recent call last):
File "E:/python/test/my/class03.py", line 36, in <module>
f.close()
NameError: name 'f' is not defined
