How to delete an entry content after click a button (Tkinter)

[carlos25]

I'm looking for a simle form to delete the entry content after pushing a button, in the next link the solution for the code works (verified it), after read that i try it, but it doesn't work for me

http://bytes.com/topic/python/answers/867449-gui-text-entry-tkinter

Python 2.7.9 [MSC v.1500 64 bit (AMD64)] on Windows 7 64 bits

this is the part of code that i can't fix:

import Tkinter

def evclr():
    chatsend.delete(0,END)

def chat(user, items, userslist):
    global chatsend
    
    v0 = Tkinter.Tk()
    v0.geometry('450x250+100+100')
    v0.title('J+ CHATTING ROOM Welcome')
    chat_msg = Tkinter.StringVar()
    
    chatwindow = Tkinter.Text(v0, height=12, width=55)
    chatwindow.insert(Tkinter.INSERT, chat_content)
    chatwindow.pack()
    
    chatsend = Tkinter.Entry(v0, bd=3, textvariable=chat_msg).pack()
    
    sendbutton = Tkinter.Button(v0, text='SEND', command=evclr).pack()

    v0.mainloop()


chat_content = '''
      Tue 07 Apr 2015
  12:11:25 
X> ===í}
éé===
'''

chat('X', [0, 2], ['CARLOS VILLALOBOS', 'CESAR BENCOMO', 'JOHNNY CASH'])

and this is what i get:

Exception in Tkinter callback
Traceback (most recent call last):
  File "C:\Python27\64\lib\lib-tk\Tkinter.py", line 1532, in __call__
    return self.func(*args)
  File "C:/Python27/Scripts/prueba04.py", line 13, in evclr
    chatsend.delete(0,END)
AttributeError: 'NoneType' object has no attribute 'delete'
Exception in Tkinter callback
Traceback (most recent call last):
  File "C:\Python27\64\lib\lib-tk\Tkinter.py", line 1532, in __call__
    return self.func(*args)
  File "C:/Python27/Scripts/prueba04.py", line 13, in evclr
    chatsend.delete(0,END)
AttributeError: 'NoneType' object has no attribute 'delete'

[bvdet]

That's because method call pack() returns None. Assign the widget instance to chatsend without calling pack(), then call chatsend.pack() on the next line.

[carlos25]

Thanks so much, i really apreciate your help and time spent