python thinker增删改查 脚本

"""
 Implement a GUI for viewing and updating class instances stored in a shelve;
 the shelve lives on the machine this script runs on, as 1 or more local files;
 """
from tkinter import *
 from tkinter.messagebox import showerror
 import shelve
 shelvename = 'class-shelve'
 fieldnames = ('name', 'age', 'job', 'pay')
class Person:
 def init(self, name, age, pay=0, job=None):
 self.name = name
 self.age  = age
 self.pay  = pay
 self.job  = job
 def lastName(self):
 return self.name.split()[-1]
 def giveRaise(self, percent):
 self.pay *= (1.0 + percent)
def makeWidgets():
 global entries
 window = Tk()
 window.title('People Shelve')
 form = Frame(window)
 form.pack()
 entries = {}
 for (ix, label) in enumerate(('key',) + fieldnames):
 lab = Label(form, text=label)
 ent = Entry(form)
 lab.grid(row=ix, column=0)
 ent.grid(row=ix, column=1)
 entries[label] = ent
 Button(window, text="Fetch",  command=fetchRecord).pack(side=LEFT)
 Button(window, text="Update", command=updateRecord).pack(side=LEFT)
 Button(window, text="Quit",   command=window.quit).pack(side=RIGHT)
 return window
def fetchRecord():
 key = entries['key'].get()
 try:
 record = db[key]                      # fetch by key, show in GUI
 except:
 showerror(title='Error', message='No such key!')
 else:
 for field in fieldnames:
 entries[field].delete(0, END)
 entries[field].insert(0, repr(getattr(record, field)))
def updateRecord():
 key = entries['key'].get()
 if key in db:
 record = db[key]                      # update existing record
 else:
 record = Person(name='?', age='?')    # eval: strings must be quoted
 for field in fieldnames:
 setattr(record, field, eval(entries[field].get()))
 db[key] = record
db = shelve.open(shelvename)
 window = makeWidgets()
 window.mainloop()
 db.close() # back here after quit or window close