tkinter：网格距离不准确

Question

我正在尝试使用tkinter绘制一个简单的网格：

from tkinter import *

root=Tk()
root.title('Mesh simulator')
window_identifiers = {}
frame_identifiers = {}
canvas_identifiers = {}
mesh_identifiers = []
window_identifiers["main_window"] = root
SETTINGS_canvas_total_width = 2048
SETTINGS_canvas_total_height = 1536
SETTINGS_canvas_visible_width = 800
SETTINGS_canvas_visible_height = 600
SETTINGS_canvas_color = "black"
SETTINGS_grid_color = "white"
mesh_density = 50

frame=Frame(window_identifiers["main_window"],width=SETTINGS_canvas_visible_width,height=SETTINGS_canvas_visible_height)
frame_identifiers["body_holder"] = frame
frame.grid(row=0,column=0)
canvas=Canvas(frame,bd=-2, bg=SETTINGS_canvas_color,width=SETTINGS_canvas_visible_width,height=SETTINGS_canvas_visible_height,scrollregion=(0,0,SETTINGS_canvas_total_width,SETTINGS_canvas_total_height), highlightthickness=0)
canvas_identifiers["main_canvas"] = canvas
canvas.grid(row=0, column=0)
i = 0
while(i<=SETTINGS_canvas_total_height):
    l = canvas_identifiers["main_canvas"].create_line(0, i, SETTINGS_canvas_total_width, i, width=1, fill=SETTINGS_grid_color)
    mesh_identifiers.append(l)
    i+=mesh_density
i = 0
while(i<=SETTINGS_canvas_total_width):
    l = canvas_identifiers["main_canvas"].create_line(i, 0, i, SETTINGS_canvas_total_height, width=1, fill=SETTINGS_grid_color)
    mesh_identifiers.append(l)
    i+=mesh_density

root.mainloop()

但是最后，当我测量两条线之间的距离时，似乎不是50px，而是大约62-64px。我不知道是什么使每平方增加了12个像素。有人可以根据我的上段代码来解释这一现象的根本原因吗？

编辑：

有趣的是，我刚刚在2个不同的显示器（笔记本电脑和22英寸显示器）上进行了测量，结果很有趣。在22英寸显示器上，一切似乎都很好（图像1），而在笔记本电脑显示器上，偏移量（图片2）

由于这不是HTML和网页设计问题，所以我现在更加困惑:)