Solution

def get_selected_row(event):
    try:
        global selected_tuple
        index=list1.curselection()[0]
        selected_tuple=list1.get(index)
        e1.delete(0,END)
        e1.insert(END,selected_tuple[1])
        e2.delete(0,END)
        e2.insert(END,selected_tuple[2])
        e3.delete(0,END)
        e3.insert(END,selected_tuple[3])
        e4.delete(0,END)
        e4.insert(END,selected_tuple[4])
    except IndexError:
        pass

Explanation

The error was fixed by simply implementing a try  and except block. When the get_selected_row  function is called, Python will execute the indented block under try . If there is an IndexError, none of the lines under try  will be executed; the line under except  will be executed, which is pass. The pass  statement means "do nothing". Therefore, the function will do nothing when there's an empty listbox.