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If the number of text items is large enough, it may be necessary to add a vertical scroll bar. You can easily connect it using the yscrollcommand option. In our example, we can wrap both widgets in a frame to keep the same layout. Remember to specify the fill option when packing the scroll so that it fills the available space in the y axis:

def __init__(self):
    self.frame = tk.Frame(self) 
    self.scroll = tk.Scrollbar(self.frame, orient=tk.VERTICAL) 
    self.list = tk.Listbox(self.frame, yscrollcommand=self.scroll.set) 
    self.scroll.config(command=self.list.yview) 
    # ... 
    self.frame.pack() 
    self.list.pack(side=tk.LEFT) 
    self.scroll.pack(side=tk.LEFT, fill=tk.Y) 

Similarly, there is a xscrollcommand option for the horizontal axis.