Python学习笔记五：错误、调试和测试

 1 # !/usr/bin/env python  
 2 # coding:utf-8                  # 编码
 3 
 4 ‘a test module‘
 5 
 6 __author__ = ‘Sunflower‘    
 7 
 8 
 9 # 异常错误类型
10 # AssertionError 断句错误
11 try:
12     my_list =[‘zhangsan‘]
13     assert len(my_list) > 0
14     my_list.pop()
15     assert len(my_list) > 0
16 except AssertionError as reason:
17     print (‘断句错误‘ + str(reason))
18 
19 
20 # IndexError
21 # KeyError   字典的访问 # my_dict.get(‘four‘)
22 # IOError 输入输出操作错误
23 # OSError  操作系统错误
24 # OverflowError  运算超出限制
25 # SyntaxError  # 语法
26 # TraceError  
27 # ZeroDivisionError 除0
28 # TypeError 类型错误
29 
30 # 调试  try ...except ...finally      raise
31 try:    #先try到错误先print，后面的指令不进行
32     f = open(‘我是一个文件.txt‘, ‘r‘)
33     print f.read()
34     f.close()
35 except IOError as reason:
36     print(‘文件出错‘ + str(reason))
37 finally:   # 绝对执行
38     f.close()
39 
40 raise IOError(‘文件出错‘)
41 
42 # else
43 # if ...else...  要不...要不...
44 # while...else...  干完...干不完...
45 # 查找最大公约数
46 def show_factor(num):
47     count = num // 2  # 除2
48     while count > 1:
49         if num % count == 0:
50             print(‘%d最大的约数是%d‘ % (num, count))
51             break
52         count -= 1
53     else:
54         print(‘%d是素数！！‘ % num)  # 执行全部执行完了就执行
55 
56 num = int(33)
57 print(show_factor(num))
58 # try...else...
59 try:
60     int(‘abc‘)
61 except ValueError as reason:
62     print(‘出错了‘+ str(reason))
63 else:
64     print(‘没有出现错‘)
65 
66 # with
67 try:
68     open(‘data.txt‘,‘w‘)
69     for each_line in f:
70         print(each_line)
71 except IOError:
72     print(‘出错了‘)
73 finally:
74     f.close()