[Tutor] problem clearing a text widget

[Chris Roy-Smith]

On 5/9/19 4:45 pm, Chris Roy-Smith wrote:
> Hi
> setup: python 3.6.8, OS Linux (ubuntu 18.04)
> 
> I have been trying to clear a text widget using the delete method, but I 
> only get the traceback below, when I click on delete button. I get this 
> message irrespective of how much text I have put into it. I'm missing 
> something, but I can't figure out what. Please can somebody point me in 
> the right direction?
> 
> regards, Chris Roy-Smith
> 
> ==============================================================
> chris at chris-X451MA:~/Scripts/python3/experiments$ ./text.py
> Exception in Tkinter callback
> Traceback (most recent call last):
>    File "/usr/lib/python3.6/tkinter/__init__.py", line 1705, in __call__
>      return self.func(*args)
>    File "./text.py", line 11, in DeleteText
>      tfield.delete(0,END)
>    File "/usr/lib/python3.6/tkinter/__init__.py", line 3139, in delete
>      self.tk.call(self._w, 'delete', index1, index2)
> _tkinter.TclError: bad text index "0"
> 
> =================================================================
> 
> code
> 
> #! /usr/bin/python3
> '''
> demo for text widget delete method
> '''
> from tkinter import *
> 
> def InsertText():
>      tfield.insert(END,"Demo only\n")
> 
> def DeleteText():
>      tfield.delete(0,END)
> 
> master=Tk()
> 
> tfield = Text(master, height=15, width=60)
> S=Scrollbar(master)
> tfield.configure(yscrollcommand=S.set)
> S.configure(command=tfield.yview)
> S.grid(row=0, column=2)
> tfield.grid(row=0, column=0, columnspan=2)
> S.config(command=tfield.yview)
> tfield.config(yscrollcommand=S.set)
> 
> Button(master, text="Insert", command=InsertText).grid(row=5, column=0)
> Button(master, text="Delete", command=DeleteText).grid(row=5, column=1)
> Button(master, text="Exit", command=master.destroy).grid(row=5, column=2)
> 
> master.mainloop()
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Never mind, the penny just dropped! The zero should be "0.0".

regards, Chris Roy-Smith