第3章 處理異常

代碼有問題時，python會顯示traceback，後面跟着一條錯誤信息。這個錯誤被稱爲異常（exception）。

 

格式

try:
    可能產生運行時錯誤的代碼
except:
    錯誤恢復代碼

測試文本

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

增長額外的代碼處理錯誤

#!/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處理錯誤

#!/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.')

錯誤

sfsdfsdfdsfsd

nisdfds ffdsdsfd

恢復代碼