1 try: 2 with open('data.txt') as f #等价于f = open('data.txt','w') 3 for each_line in f: 4 print(each_line) 5 6 except OSError as reason: #使用异常处理执行到这一步时边不会再执行后面的语句,因此常常是f.close()不能执行而出问题,上面的with语句可以有效解决该问题
7 print('出错啦'+str(reason))
使用with语句可以处理多个项目用 ‘,’隔开,例如
with A() as a:
with B() as b:
suite
可以写成:
with A() as a, B() as b:
suite