[Tkinter] canvas widget scroll issue

[chrisdb]

Hi,

I have a canvas inside a frame that contains 3 entry widgets, but for some reason ,when I scroll up, the widgets move down, althoug there is no space above these entries.

Below is my code:

import tkinter as tk

class Application(tk.Frame):
    def __init__(self, master: tk.Tk = None):
        super().__init__(master)
        self.master = master
        self.grid(row=0)
        self.create_widgets()

    def create_widgets(self):
        # Table view with entries in scrollable frame
        self.scroll_frame = ScrollableFrame(self.master)
        self.scroll_frame.grid(row=4, column=0,  columnspan = 5, padx = (10, 10), sticky="W")
        
        tab_entry = tk.Entry(self.scroll_frame.scrollable_frame, relief=tk.GROOVE, width = 191)
        tab_entry.grid(row=1, column=0, sticky=tk.NSEW)
        tab_entry1 = tk.Entry(self.scroll_frame.scrollable_frame, relief=tk.GROOVE, width = 191)
        tab_entry1.grid(row=2, column=0, sticky=tk.NSEW)
        tab_entry2 = tk.Entry(self.scroll_frame.scrollable_frame, relief=tk.GROOVE, width = 191)
        tab_entry2.grid(row=3, column=0, sticky=tk.NSEW)

class ScrollableFrame(tk.Frame):
    """ Create a scrollable frame for use with 'Entry' widgets in table form
        
    Attributes:
        canvas (tkinter.Canvas)
        scrollable_frame (tkinter.Frame): frame for use inside canvas to enable scrolling of widgets
    """
    def __init__(self, container: tk.Tk, *args, **kwargs):
        super().__init__(container, *args, **kwargs)

        self.canvas = tk.Canvas(self, scrollregion=(0, 0, 1150, 180), width = 1150, height = 180, bg='white' )

        scrollbar_y = tk.Scrollbar(self, orient="vertical", command=self.canvas.yview)
        scrollbar_x = tk.Scrollbar(self, orient="horizontal", command=self.canvas.xview)
        
        # reset the view
        self.canvas.xview_moveto(0)
        self.canvas.yview_moveto(0)

        self.scrollable_frame = tk.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_y.set, xscrollcommand=scrollbar_x.set)
        
        self.canvas.bind_all("<MouseWheel>", self._on_mousewheel)

        self.canvas.grid(row=0, column=0, sticky="news")
        scrollbar_y.grid(row=0, column=1, sticky='ns')
        scrollbar_x.grid(row=1, column=0, sticky='ew')
        
        
        
    def _on_mousewheel(self, event: tk.Event):
        self.canvas.yview_scroll(int(-1*(event.delta/120)), "units")

        
if __name__ == '__main__':
    root = tk.Tk()
    root.title("test")
    root.geometry('{}x{}+{}+{}'.format(1200, 620, 40, 40))
    root.resizable(0,0)
    app = Application(master=root)
    app.mainloop()

Is there a reason why this strange scroll issue occurs?
I'm running this on Windows with Python 3.9.

Thank you