第3章 处理异常

Posted 2020-08-28

代码有问题时，python会显示traceback，后面跟着一条错误信息。这个错误被称为异常（exception）。

 

格式

try:
    可能产生运行时错误的代码
except:
    错误恢复代码

测试文本

Man: Is this your car?
Other man: No.
Woman: What color is it?
Bye.
Go on

增加额外的代码处理错误

#!/usr/local/python
with open(‘E:/python code/other/tmp/test.txt‘) as fd:
    for each_line in fd:
        if each_line.find(‘:‘) > 0:
            (role, line_spoken) = each_line.split(‘:‘,1)
            print(role),
            print(‘ said ‘),
            print(line_spoken),

使用try-except处理错误

#!/usr/local/python
import os,sys
try:
    with open(‘E:/python code/other/tmp/test.txt‘) as fd:
        for each_line in fd:
            try:
                (role, line_spoken) = each_line.split(‘:‘, 1)
                print(role),
                print(‘ said ‘),
                print(line_spoken),
            except ValueError:
                pass
except IOError:
    print(‘The file is missing.‘)

错误

sfsdfsdfdsfsd

nisdfds ffdsdsfd

恢复代码