在tkinter中扩展多个框架

Question

I am trying to get the equivalent of the red box on the bottom(in my real program it is labels and checkboxes) to expand to the size of the green box on top(which is also checkboxes in my real program). Fill and expand both seem to be not working. I can't just change the widths either. What am i doing wrong?

try:
    from tkinter import *
except ImportError:
    from Tkinter import *

class Application(Frame):
    def __init__(self,master=None):
        root = Tk()
        Frame.__init__(self,master)

        topframe = Frame(self)
        botframe = Frame(self)

        Frame(topframe, background="green", width=300, height = 200).grid(row =0, column = 0)
        Frame(botframe, background="red", width=200, height = 200).grid(row =1, column = 0, sticky = E)

        topframe.pack(side = TOP)
        botframe.pack(side = BOTTOM, fill = BOTH, expand = True)

        self.pack(fill="both", expand=True)
        root.mainloop()
Application()

Answer 1

I fixed it, take a look if you have a similar problem

try:
    from tkinter import *
except ImportError:
    from Tkinter import *

class Application(Frame):
    def __init__(self,master=None):
        root = Tk()
        Frame.__init__(self,master)

        topframe = Frame(root)
        botframe = Frame(root)

        topframe.grid(row =0, column = 0, sticky=N+E+W)
        botframe.grid(row =1, column = 0, sticky=S+E+W)

        topframe.columnconfigure(0, weight=1)
        botframe.columnconfigure(0, weight=1)

        Frame(topframe, background="green", width=300, height = 200).grid(row =0, column = 0, sticky=N+E+W)
        Frame(botframe, background="red", width=200, height = 200).grid(row =1, column = 0, sticky = S+E+W)

        root.mainloop()
Application()

Answer 2

When you use grid, a rule of thumb is that you should grid_rowconfigure and grid_columnconfigure to give at least one row and one column a non-zero weight. This will cause that row and that column to "take up the slack" in a layout.