import tkinter
 from tkinter import messagebox

 def cmd():
     global n
     global buttontext
     n += 1
     if n==1:
         messagebox.askokcancel('Python Tkinter', 'askokcancel')
         buttontext.set('askquestion')
     elif n==2:
         messagebox.askquestion('Python Tkinter', 'askquestion')
         buttontext.set('askyesno')
     elif n==3:
         messagebox.askyesno('Python Tkinter', 'askyesno')
         buttontext.set('showerror')
     elif n==4:
         messagebox.showerror('Python Tkinter', 'showerror')
         buttontext.set('showinfo')
     elif n==5:
         messagebox.showinfo('Python Tkinter', 'showinfo')
         buttontext.set('showwarning')
     else:
         n = 0
         messagebox.showwarning('Python Tkinter', 'showwarning')
         buttontext.set('askokcancel')

 n = 0
 root = tkinter.Tk()
 buttontext = tkinter.StringVar()
 buttontext.set('askokcancel')
 button = tkinter.Button(root, textvariable=buttontext, command=cmd)
 button.pack()
 root.mainloop()

 import tkinter
 from tkinter import simpledialog

 def inputStr():
     r = simpledialog.askstring('Python Tkinter', 'Input String', initialvalue = 'Python Tkinter')
     print(r)
 def inputInt():
     r = simpledialog.askinteger('Python Tkinter', 'Input Integer')
     print(r)
 def inputFloat():
     r = simpledialog.askfloat('Python Tkinter', 'Input Float')
     print(r)

 root = tkinter.Tk()
 btn1 = tkinter.Button(root, text='Input String', command=inputStr)
 btn2 = tkinter.Button(root, text='Input Integer', command=inputInt)
 btn3 = tkinter.Button(root, text='Input Float', command=inputFloat)

 btn1.pack(side='left')
 btn2.pack(side='left')
 btn3.pack(side='left')

 root.mainloop()

 import tkinter
 from tkinter import filedialog

 def openfile():
     r = filedialog.askopenfilename(title='打开文件', filetypes=[('Python', '*.py *.pyw'), ('All Files', '*')])
     print(r)
 def savefile():
     r = filedialog.asksaveasfilename(title='保存文件', initialdir='d:\mywork', initialfile='hello.py')
     print(r)

 root = tkinter.Tk()
 btn1 = tkinter.Button(root, text='File Open', command=openfile)
 btn2 = tkinter.Button(root, text='File Save', command=savefile)

 btn1.pack(side='left')
 btn2.pack(side='left')
 root.mainloop()