Yep, you’re spot-on—this is a classic case of Tkinter’s platform-specific theme differences causing headaches. macOS’s default Aqua theme adds extra padding and spacing to widgets to align with Apple’s design guidelines, while Windows uses a far more compact default theme. Here are concrete, actionable fixes to get that tight, Windows-like layout working on macOS:

1. Switch to a Cross-Platform Themed Widget Set (ttk) #

Tkinter’s ttk (themed widgets) module includes themes that behave consistently across operating systems. Ditching regular Button/Entry for ttk versions and setting a universal theme will strip away macOS’s extra default padding. Here’s how to adjust your code:

from tkinter import *
from tkinter import ttk

root = Tk()
root.title("Simple Calculator")

# Force a cross-platform theme (clam/alt work best for compact layouts)
style = ttk.Style(root)
style.theme_use('clam')

# Replace Entry with ttk.Entry
e = ttk.Entry(root, width=35)
e.grid(row=0, column=0, columnspan=3, padx=10, pady=10)

def button_click(number):
    e.insert(0, number)

# Replace all regular Buttons with ttk.Buttons
button_1 = ttk.Button(root, text="1", command=lambda: button_click(1))
button_2 = ttk.Button(root, text="2", command=lambda: button_click(2))
button_3 = ttk.Button(root, text="3", command=lambda: button_click(3))
button_4 = ttk.Button(root, text="4", command=lambda: button_click(4))
button_5 = ttk.Button(root, text="5", command=lambda: button_click(5))
button_6 = ttk.Button(root, text="6", command=lambda: button_click(6))
button_7 = ttk.Button(root, text="7", command=lambda: button_click(7))
button_8 = ttk.Button(root, text="8", command=lambda: button_click(8))
button_9 = ttk.Button(root, text="9", command=lambda: button_click(9))
button_0 = ttk.Button(root, text="0", command=lambda: button_click(0))
button_add = ttk.Button(root, text="+", command=lambda: button_click(7))
button_equal = ttk.Button(root, text="=", command=lambda: button_click(7))
button_clear = ttk.Button(root, text="clear", command=lambda: button_click(7))

# Add sticky="nsew" to make buttons fill their grid cells
button_1.grid(row=3, column=0, sticky="nsew")
button_2.grid(row=3, column=1, sticky="nsew")
button_3.grid(row=3, column=2, sticky="nsew")
button_4.grid(row=2, column=0, sticky="nsew")
button_5.grid(row=2, column=1, sticky="nsew")
button_6.grid(row=2, column=2, sticky="nsew")
button_7.grid(row=1, column=0, sticky="nsew")
button_8.grid(row=1, column=1, sticky="nsew")
button_9.grid(row=1, column=2, sticky="nsew")
button_0.grid(row=4, column=0, sticky="nsew")
button_add.grid(row=5, column=0, sticky="nsew")
button_equal.grid(row=5, column=1, columnspan=2, sticky="nsew")
button_clear.grid(row=4, column=1, columnspan=2, sticky="nsew")

# Configure columns to expand evenly (eliminates empty gaps between columns)
for col in range(3):
    root.grid_columnconfigure(col, weight=1)

root.mainloop()

2. Adjust Tkinter’s Scaling Factor #

macOS defaults to a scaling factor of 1.33 (to accommodate Retina displays), which can make widgets and spacing appear larger than intended. Resetting it to 1.0 will shrink elements to a more compact size:

Add this line immediately after creating your root window:

root.tk.call('tk', 'scaling', 1.0)

3. Use Grid Configuration to Eliminate Unwanted Gaps #

Your original code uses fixed padx/pady values, but macOS adds its own internal padding to widgets. Using sticky="nsew" forces widgets to fill their entire grid cell, while configuring column/row weights ensures empty space is distributed evenly instead of creating gaps between elements.

For example, adding this after placing all widgets will make your layout more consistent:

# Make columns expand proportionally
for col in range(3):
    root.grid_columnconfigure(col, weight=1)
# Make rows expand proportionally
for row in range(1, 6):
    root.grid_rowconfigure(row, weight=1)

Why This Happens #

Tkinter relies on native system themes by default. macOS’s Aqua theme prioritizes visual "breathing room" per Apple’s design standards, so buttons, entries, and grid spacing get extra padding. Windows’s default theme is utility-focused, keeping elements tight and compact. By overriding the theme or adjusting scaling, you bypass these platform-specific defaults.

Combining these fixes—using ttk widgets with a cross-platform theme plus adjusting scaling—should get you a layout nearly identical to what you see on Windows.

内容的提问来源于stack exchange，提问作者Argileon