Question

here is some code:

from Tkinter import *

class Main(object):

    def __init__(self):
        self.console = Text(root, relief='groove', cursor='arrow', spacing1=3)
        self.console.insert(INSERT, '>>> ')
        self.console.focus_set()
        self.scroll = Scrollbar(root, cursor='arrow', command=self.console.yview)
        self.console.configure(yscrollcommand=self.scroll.set)

        self.scroll.pack(fill='y', side='right')
        self.console.pack(expand=True, fill='both')

root = Tk()
root.geometry('%sx%s+%s+%s' %(660, 400, 40, 40))
root.option_add('*font', ('Courier', 9, 'bold'))
root.resizable(0, 1)
app = Main()
root.mainloop()

is there some way to make ‘>>> ‘ become unremovable(like in IDLE for example)?
thanks in advance.

Answer 1

Take a look at IDLE’s source code. In particular look at ‘smart_backspace_event’ in EditorWindow.py. IDLE binds <Key-Backspace> on the text widget to this function (indirectly through the <<smart-backspace>> event).

The basic code you’ll need follows like this:

chars = console.get("insert linestart", "insert")
# [Do some analysis on "chars" to detect >>> and prevent a backspace]

if DO_BACKSPACE: 
    console.delete("insert-1c", "insert")

# "break" is important so that the Text widget's backspace handler doesn't get called
return "break"