import tkinter as tk

def fin_04():
    """Create a program that will display the following screen:
        +-------------------------------------------------+
        |                  ___________   ________________ |
        | Enter a number: |___________| |View Times Table||
        |                  ___________  |________________||
        |                 |           |  ________________ |
        |                 |           | |     Clear      ||
        |                 |           | |________________||
        |                 |           |                   |
        |                 |           |                   |
        |                 |___________|                   |
        |_________________________________________________|
        When the user enters a number in the first box and clicks on the "View
        Times Table" button it should show the times table in the list area.
        For instance, if the user entered 99 they would see the list as shown
        in the example on the right. The "Clear" button should clear both boxes."""
    com_bg = "dodger blue"
    window = tk.Tk()
    window.title("Tablas de Multiplicar")
    window.geometry("400x300")
    window["bg"] = com_bg

    lbl_num = tk.Label(text="Ingresa un número:", font="Verdana 10")
    lbl_num["bg"] = com_bg
    lbl_num.place(x=20, y=20, width=130, height=30)

    txt_in = tk.Entry()
    txt_in.place(x=150, y=20, width=120, height=30)

    def view():
        num = txt_in.get()
        clear()
        if num.isdigit():
            num = int(num)
            for i in range(1,13):
                lst_table.insert('end', f"{i} x {num} = {i*num}")
        else:
            clear()
    
    def clear():
        lst_table.delete(0, 'end')
        txt_in.delete(0, 'end')
        txt_in.focus()

    btn_view = tk.Button(text="Ver tablas", width=100, height=30, command=view)
    btn_view.place(x=280, y=20, width=100, height=30)

    lst_table = tk.Listbox()
    lst_table["justify"] = "left"
    lst_table.place(x=150, y=60, width=120 ,height=230)

    btn_clear = tk.Button(text="Limpiar", width=100, height=30, command=clear)
    btn_clear.place(x=280, y=60, width=100, height=30)

    txt_in.focus()

    window.mainloop()