Grid fill empty space in scrollable area tkinter - python-3.x

Question

I'm buildinging a gui with a list of labels in a scrollable area. Now I want that the labels fill the empty space via grid manager. So I use the columnconfigure(0, weight=1) and rowconfigure(0, weight=1) method. It works fine for the scrollbar but not for the labels inside the scrollable area. Example showing my issue:
class app():
def __init__(self):
self.root = tk.Tk()
self.root.geometry("341x448")
self.root.minsize(340,440)
self.root.rowconfigure(0, weight=1)
self.root.columnconfigure(0, weight=1)
def display(self):
self.container = ttk.Frame(self.root)
self.container.rowconfigure(0, weight=1)
self.container.columnconfigure(0, weight=1)
self.canvas = tk.Canvas(self.container)
scrollbar = ttk.Scrollbar(self.container, orient = tk.VERTICAL, command = self.canvas.yview)
self.scrollable_frame = ttk.Frame(self.canvas)
self.scrollable_frame.bind(
"<Configure>",
lambda e: self.canvas.configure(
scrollregion=self.canvas.bbox("all")))
self.canvas.create_window((0, 0), window = self.scrollable_frame, anchor = "nw")
self.canvas.configure(yscrollcommand = scrollbar.set)
for i in range(15):
Label = ttk.LabelFrame(self.scrollable_frame, text = "Sample scrolling label")
Label.grid(row = i, column = 0, columnspan=2, sticky=tk.NSEW)
Label.columnconfigure(0, weight=1)
Button = ttk.Button(Label, text=f"Button {i}")
Button.grid(row=0, column=0, sticky=tk.NW)
self.container.grid(row = 0, column = 0, sticky = "nswe")
self.canvas.grid(row = 0, column = 0, sticky = 'nswe')
scrollbar.grid(row = 0, column = 2, sticky = "ns")
self.root.mainloop()
if __name__ =="__main__":
start = app()
start.display()

Answer 1

There are a couple of reasons why your labels do not fill the horizontal space:
You grid the labels in self.scrollable_frame but you have not configured its grid to expand. You need to add
self.scrollable_frame.columnconfigure(0, weight=1)
You have not set the width and height of self.scrollable_frame when you put it in the canvas, so by default, it stays the size it needs to display all its content. If you want it to expand to fill all the space available in the canvas, you can bind the canvas resizing event to a function that will resize the frame accordingly. So add
self.canvas.bind("<Configure>", self.resize)
in self.display() and create the self.resize() function
def resize(self, event):
w = self.scrollable_frame.winfo_reqwidth()
h = self.scrollable_frame.winfo_reqheight()
self.canvas.itemconfigure(1, width=max(w, event.width), height=max(h, event.height))
that makes the frame expand if the canvas is larger than the minimum size required to display all the widgets.
By the way, I suggest you to follow PEP 8 style guide, especially for names, e.g. capitalize class names but not variable names. And above all, be consistent, it will make the code clearer and easier to understand. In particular, I find using Label and Button as variable names quite confusing as they are class names in tkinter.