I feel like I am missing something very basic here. This is my first try creating a GUI in Python. I try to add several frames inside my main window and place stuff inside by using grid manager. The frame creation and sizing and stuff works fine, until I add anything inside the frame. Like in this example with only one frame, when I put my dummy label, the frame just completely vanishes and only the label is displayed.
I really want to understand what is going on and why it is behaving like it is ... and of course, how to fix it. Thanks a lot.
from tkinter import *
window = Tk()
# Window geometry
window.title("Tk")
window.geometry('850x600')
# Set Frames
LeftTopFrame = Frame(window,bg='red',height=200,width=300)
LeftTopFrame.pack(fill=X,side=LEFT)
lblInp = Label(LeftTopFrame, text='Label',font=('Tahoma', 10))
lblInp.grid(column=0,row=0)
window.mainloop()