Get the index of a selected item in a ttk.Combobox

Question: Get the index of a selected item in a ttk.Combobox

Core point: Use <seq>.index to get the index of the selected item

Reference

• s.index(x[, start[, end]])

  Return zero-based index in the seq of the first item whose value is equal to x

• Combobox.get()

  The .get() method returns the current selected item of the Combobox

• simple-ttk-combobox-demo

  Bind the virtual event <<ComboboxSelected>> to the Combobox widget

import tkinter as tkimport tkinter.ttk as ttkclass App(tk.Tk):    def __init__(self):        super().__init__()                self.combobox = combobox = ttk.Combobox(self)        combobox['values'] = ("Speed, Distance, Time",                              "Speed, Acceleration, Time",                              "Gravitational Potential Energy(Ep)"                              )        combobox.pack()                button = tk.Button(text="Submit", command=self.on_clicked)        button.pack()        def on_clicked(self, *event):        selected = self.combobox.get()        if selected:            idx = self.combobox['values'].index(selected)            print('simpleFormulaMenu({}), selected: {}'.format(idx, selected))                        if idx in (2, 3, 4):  # pass                pass            else:                # simpleFormulaMenu(idx)                passif __name__ == '__main__':    App().mainloop()

Tested with Python: 3.5 - 'TclVersion': 8.6 'TkVersion': 8.6