Tkinter - Run Event Function Upon Listbox Selection

I have a ListboxSelect event binding to my listbox, lb. I am using selection_set to select an item in the listbox, but the binded function doesn't run. How can I make the function run when I select an item in the listbox using selection_set as well as when it is clicked?

import tkinter as tk

class SampleApp(tk.Tk):
    def __init__(self, *args, **kwargs):
        tk.Tk.__init__(self, *args, **kwargs)
        self.lb = tk.Listbox(self)

        for x in range(20):
            self.lb.insert("end", x)

        self.lb.bind("<<ListboxSelect>>", self.OnSelect)

        self.lb.pack(side="top", fill="both", expand=True)


    def OnSelect(self, event):
        print(event.widget.get(event.widget.curselection()[0]))
        self.lb.selection_set(10)


if __name__ == "__main__":
    app = SampleApp()
    app.mainloop()