Cannot use geometry manager pack inside

user3623888 picture user3623888 · May 10, 2014 · Viewed 107.3k times · Source

So I'm making an rss reader using the tkinter library, and in one of my methods I create a text widget. It displays fine until I try to add scrollbars to it.

Here is my code before the scrollbars:

   def create_text(self, root):
        self.textbox = Text(root, height = 10, width = 79, wrap = 'word')
        self.textbox.grid(column = 0, row = 0)

Here is my code after:

def create_text(self, root):
        self.textbox = Text(root, height = 10, width = 79, wrap = 'word')
        vertscroll = ttk.Scrollbar(root)
        vertscroll.config(command=self.textbox.yview)
        vertscroll.pack(side="right", fill="y", expand=False)
        self.textbox.config(yscrllcommand=vertscroll.set)
        self.textbox.pack(side="left", fill="both", expand=True)
        self.textbox.grid(column = 0, row = 0)

This gives me the error

_tkinter.TclError: cannot use geometry manager pack inside .56155888 which already has slaves managed by grid on the line vertscroll.pack(side="right", fill="y", expand=False)

Any ideas how to fix this?

Answer

unutbu picture unutbu · May 10, 2014

Per the docs, don't mix pack and grid in the same master window:

Warning: Never mix grid and pack in the same master window. Tkinter will happily spend the rest of your lifetime trying to negotiate a solution that both managers are happy with. Instead of waiting, kill the application, and take another look at your code. A common mistake is to use the wrong parent for some of the widgets.

Thus, if you call grid on the textbox, do not call pack on the scrollbar.


import Tkinter as tk
import ttk

class App(object):
    def __init__(self, master, **kwargs):
        self.master = master
        self.create_text()

    def create_text(self):
        self.textbox = tk.Text(self.master, height = 10, width = 79, wrap = 'word')
        vertscroll = ttk.Scrollbar(self.master)
        vertscroll.config(command=self.textbox.yview)
        self.textbox.config(yscrollcommand=vertscroll.set)
        self.textbox.grid(column=0, row=0)
        vertscroll.grid(column=1, row=0, sticky='NS')

root = tk.Tk()
app = App(root)
root.mainloop()