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