需要注意的几点：
1.list的初始化
2.cPickle的load和dump方法的使用
3.class的存储
4.sort函数的使用
5.global标签的使用
6.初始的时候不存在memberlist.data或者文件内容为空解决方法
1 #Filename:MyAddressBook.py
2 import cPickle as p
3 import os
4 #Class Item
5 class Item:
6 def __init__(self,name,age,gender):
7 self.name = name
8 self.age = age
9 self.gender = gender
10 #the main menu of address book
11 def menu():
12 '''the main menu of address book'''
13 print ''
14 print '1.Insert an item'
15 print '2.Delete an item'
16 print '3.Modify an item'
17 print '4.Display all items'
18 print '5.Sort all items'
19 print '6.Exit the program'
20 print 'What do you want to do?'
21
22 #initialization of system, load the member list
23 def begin():
24 '''initialization of system, load the member list'''
25 global itemlist
26 if os.path.exists('memberlist.data') == True:#to judge whether the file exists
27 listfile = file('memberlist.data','r')
28 if len(listfile.read())!=0:#to judge whether the file is empty
29 itemlist = p.load(listfile)
30 listfile.close()
31 #exitance of system, store the menber list
32 def end():
33 '''exitance of system, store the menber list'''
34 global itemlist
35 listfile = file('memberlist.data','w+')
36 p.dump(itemlist,listfile)
37 listfile.close()
38 #insert an item into the member list
39 def insert():
40 '''insert an item into the member list'''
41 name = raw_input('Enter name:')
42 age = int(raw_input('Enter age:'))
43 gender = raw_input('Enter gender:')
44 item = Item(name,age,gender)
45 global itemlist
46 itemlist.append(item)
47 #print an item
48 def output(item):
49 '''print an item'''
50 print '%-15s%-5d%s'%(item.name,item.age,item.gender)
51 #print all items
52 def display():
53 '''print all items'''
54 global itemlist
55 l = len(itemlist)
56 print 'name age gender'
57 for i in range(0,l):
58 output(itemlist[i])
59 print ''
60 #delete an item by name from member list
61 def delete():
62 '''delete an item by name from member list'''
63 name = raw_input('Enter the name you want to delete:')
64 global itemlist
65 l = len(itemlist)
66 for i in range(0,l):
67 if (itemlist[i].name == name):
68 itemlist.pop(i)
69 #update an item
70 def update(item):
71 '''update an item'''
72 item.name = raw_input('Enter name:')
73 item.age = int(raw_input('Enter age:'))
74 item.gender = raw_input('Enter gender:')
75 #update an item's information by name
76 def modify():
77 '''update an item's information by name'''
78 name = raw_input('Enter the name you want to modify:')
79 global itemlist
80 l = len(itemlist)
81 for i in range(0,l):
82 if (itemlist[i].name == name):
83 update(itemlist[i])
84 print 'Update done!'
85 #sort all items by name
86 def sort():
87 global itemlist
88 itemlist.sort(None,key = lambda item:item.name)
89 #Here are the scripts
90 itemlist = [] #Notice here!!!
91 begin()
92 while True:
93 menu()
94 sel = int(raw_input())
95 if sel == 1:
96 insert()
97 elif sel == 2:
98 delete()
99 elif sel == 3:
100 modify()
101 elif sel == 4:
102 display()
103 elif sel == 5:
104 sort()
105 else:
106 break
107 end()
108 print 'Good Bye!'