Objects in Python(Chapter 2 of Python 3 Object Oriented Programming)

时间：2010-08-31 来源：Ray Z

notebook 1 import datetime
2
3 last_id = 0
4
5 class Note:
6
7     def __init__(self, memo, tags=''):
8         self.memo = memo
9         self.tags = tags
10         self.creation_date = datetime.date.today()
11         global last_id
12         last_id += 1
13         self.id = last_id
14
15     def match(self, filter):
16         return filter in self.memo or filter in self.tags
17
18 class Notebook:
19
20     def __init__(self):
21         self.notes = []
22
23     def new_note(self, memo, tags=''):
24         self.notes.append(Note(memo, tags))
25
26     def _find_note(self, note_id):
27         for note in self.notes:
28             if note.id == str(note_id):
29                 return note
30         return None
31
32     def modify_memo(self, note_id, memo):
33         note = self._find_note(note_id)
34         if note:
35             note.memo = memo
36             return True
37         return False
38
39     def modify_tags(self, note_id, tags):
40         note = self._find_note(note_id)
41         if note:
42             note.tags = tags
43             return True
44         return False
45
46     def search(self, filter):
47         return [note for note in self.notes if note.match(filter)]

menu 1 import sys
2 from notebook import Notebook, Note
3
4 class Menu:
5     def __init__(self):
6         self.notebook = Notebook()
7         self.choices = {
8             "1" : self.show_notes,
9             "2" : self.search_notes,
10             "3" : self.add_note,
11             "4" : self.modify_note,
12             "5" : self.quit
13             }
14
15     def display_menu(self):
16         print("""
17 Notebook Menu
18
19 1. Show all Notes
20 2. Search Notes
21 3. Add Note
22 4. Modify Note
23 5. Quit
24 """)
25
26     def run(self):
27         while True:
28             self.display_menu()
29             choice = input("Enter an option: ")
30             action = self.choices.get(choice)
31             if action:
32                 action()
33             else:
34                 print("{0} is not a valid choice".format(choice))
35
36     def show_notes(self, notes=None):
37         if not notes:
38             notes = self.notebook.notes
39             for note in notes:
40                 print("{0}: {1}\n{2}".format(note.id, note.tags, note.memo))
41
42     def search_notes(self):
43         filter = input("Search for: ")
44         notes = self.notebook.search(filter)
45         self.show_notes(notes)
46
47     def add_note(self):
48         memo = input("Enter a memo:")
49         self.notebook.new_note(memo)
50         print("Your note has been added.")
51
52     def modify_note(self):
53         id = input("Enter a note id:")
54         memo = input("Enter a memo:")
55         tags = input("Enter tags:")
56         if memo:
57             self.notebook.modify_memo(id, memo)
58         if tags:
59             self.notebook.modify_tags(id, tags)
60
61     def quit(self):
62         print("Thank you for using your notebook today.")
63         sys.exit(0)
64
65 if __name__ == "__main__":
66     Menu().run()
67