Expand Text widget to fill the entire parent Frame in Tkinter

When using grid, any extra space in the parent is allocated proportionate to the "weight" of a row and/or a column (ie: a column with a weight of 2 gets twice as much of the space as one with a weight of 1). By default, rows and columns have a weight of 0 (zero), meaning no extra space is given to them.

You need to give the column that the widget is in a non-zero weight, so that any extra space when the window grows is allocated to that column.

root.grid_columnconfigure(0, weight=1)

You'll also need to specify a weight for the row, and a sticky value of N+S+E+W if you want it to grow in all directions.

Since your window only contains one widget and you want this widget to fill the entire window, it would be easier to use the pack geometry manager instead of grid

input_text_area.pack(expand=True, fill='both')

expand=True tells Tkinter to allow the widget to expand to fill any extra space in the geometry master. fill='both' enables the widget to expand both horizontally and vertically.

from tkinter import *root = Tk()input_text_area = Text(root)input_text_area.grid(row=0, column=0, columnspan=4, sticky=N+S+W+E)input_text_area.configure(background='#4D4D4D')root.grid_columnconfigure(0, weight=1)root.grid_rowconfigure(0, weight=1)root.mainloop()

not sure if this is what you want. but this fills the entire screen.