python2.7写的图形密码生成器

#coding:utf8
import random,wx
def password(event):
    a = [chr(i) for i in range(97,123)]
    b = [chr(i) for i in range(65,91)]
    c = ['0','1','2','3','4','5','6','7','8','9']
    d = ['!','@','#','$','%','^','&','*','(',')','=','_','+','/','?']

    set1 = a + b + c + d
    set2 = a + b + c
    num = int(length.getvalue())
    if switch.getvalue() == 0:
        passwd = ''.join(random.sample(set1,num))
        contents.setvalue(passwd)
    else:
        passwd = ''.join(random.sample(set2,num))
        contents.setvalue(passwd)
app = wx.app()
win = wx.frame(none,-1,title=u'密码生成器',size=(480,200))
bkg = wx.panel(win,-1)

# tt = wx.statictext(bkg,-1,u'屏蔽输入字符')
# delete = wx.textctrl(bkg,-1)


right = wx.button(bkg,-1,label=u'确定生成')
right.bind(wx.evt_button,password)

stxt = wx.statictext(bkg,-1,u'请输入你的密码长度位数！' )
length = wx.textctrl(bkg,-1,size=(50,27))
switch = wx.checkbox(bkg, -1,u'关闭特殊字符',(150, 20))

sobx = wx.boxsizer()
sobx.add(stxt,proportion=0,flag=wx.all,border=5)
sobx.add(length,proportion=1,border=5)
sobx.add(switch,proportion=0,flag=wx.all | wx.align_right,border=5)

sobx.add(right,proportion=0,flag=wx.expand,border=5)

contents = wx.textctrl(bkg,-1)
cobx = wx.boxsizer()
cobx.add(contents,proportion=1,flag=wx.expand,border=5)

dobx = wx.boxsizer()

# dobx.add(delete,proportion=1,flag=wx.all,border=5)


robx = wx.boxsizer(wx.vertical)
robx.add(cobx,proportion=1,flag=wx.expand | wx.all,border=5)
robx.add(sobx,proportion=0,flag=wx.all,border=5)
# robx.add(dobx,proportion=0,flag=wx.expand,border=5)

bkg.setsizer(robx)

win.show()
app.mainloop()