Making Tkinter Layout Responsive with Expandable Upper Section

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1

Layout Issue with Tkinter GUI Design

I’m building my first Python GUI application using Tkinter and I’m having trouble making the layout responsive. My current design has two main sections but when I resize the window, the top area doesn’t expand properly.

What I want to achieve is keeping the bottom control panel fixed in size while allowing the upper display area to grow and fill the remaining space when the window is resized.

import tkinter as tk

main_window = tk.Tk()

# Upper display area
display_frame = tk.Frame(main_window)
display_frame.pack(side=tk.TOP, fill=tk.BOTH)

# Scrollbar for the list
vert_scrollbar = tk.Scrollbar(display_frame)
vert_scrollbar.pack(side=tk.RIGHT, fill=tk.Y)

# Main list widget
data_listbox = tk.Listbox(display_frame)
data_listbox.pack(fill=tk.BOTH)

# Sample data
for num in range(50):
    data_listbox.insert(tk.END, f"Item {num}")

# Connect scrollbar to listbox
data_listbox.config(yscrollcommand=vert_scrollbar.set)
vert_scrollbar.config(command=data_listbox.yview)

# Control panel at bottom
control_frame = tk.Frame(main_window)
control_frame.pack(side=tk.BOTTOM, fill=tk.X)

# Input fields section
input_section = tk.Frame(control_frame)
input_section.pack(side=tk.LEFT, fill=tk.X)

# Form labels and entries
tk.Label(input_section, text="Name").grid(row=0, column=0, sticky=tk.E)
tk.Label(input_section, text="Email").grid(row=0, column=2, sticky=tk.E)
tk.Label(input_section, text="Phone").grid(row=0, column=4, sticky=tk.E)

name_var = tk.StringVar()
email_var = tk.StringVar()
phone_var = tk.StringVar()

tk.Entry(input_section, textvariable=name_var).grid(row=0, column=1)
tk.Entry(input_section, textvariable=email_var).grid(row=0, column=3)
tk.Entry(input_section, textvariable=phone_var).grid(row=0, column=5)

# Button panel
button_panel = tk.Frame(control_frame)
button_panel.pack(side=tk.RIGHT)

# Action buttons
tk.Button(button_panel, text="Show All", width=10).grid(row=0, column=0)
tk.Button(button_panel, text="Find", width=10).grid(row=1, column=0)
tk.Button(button_panel, text="Insert", width=10).grid(row=2, column=0)
tk.Button(button_panel, text="Modify", width=10).grid(row=3, column=0)
tk.Button(button_panel, text="Remove", width=10).grid(row=4, column=0)

main_window.mainloop()

The current setup doesn’t expand the list area properly when I maximize the window. How can I make the top section responsive while keeping the bottom controls fixed?

2

Your display frame is missing the expand parameter. Without it, Tkinter won’t give the frame any extra space when the window grows - it just stays at minimum size. Add expand=True to your display frame’s pack configuration and you’re done. I hit this same issue building a database viewer last year. Here’s what’s happening: the expand parameter works with fill to control how widgets grab space. Your bottom control panel stays fixed because it only uses fill=tk.X without expand, which is exactly what you want - main content area that grows and a fixed toolbar.

3

yeah, you’re totally right about expand=True on the display_frame. without it, tkinter just sticks to the min size. trust me, i’ve hit this snag a bunch of times. once you add that, your listbox will spread out nicely above those controls!

4

interesting issue! the display_frame probably isn’t expanding properly. try adding expand=True to your pack call: display_frame.pack(side=tk.TOP, fill=tk.BOTH, expand=True). that’ll make it grab the extra space when you resize. are you planning to add more widgets to that display area later?