Q:

I would like to create a tkinter Python button that activates more than one command when I press one button

I want a button that activates two functions to calculate the tax assessment value of a property then the tax on the assessed value of the property with one button click.
The button should say 'Calculate' and should activate a .6 * property value function and a .0064 * the value of the assessment.
import tkinter

class PropertyTaxGUI:

    def __init__(self):

        self.main_window = tkinter.Tk()

        self.top_frame = tkinter.Frame()
        self.mid_frame = tkinter.Frame()
        self.third_frame = tkinter.Frame()
        self.bottom_frame = tkinter.Frame()

        self.prompt_label = tkinter.Label(self.top_frame, \
                                    text='Enter the property value: $')
        self.property_entry = tkinter.Entry(self.top_frame, \
                                             width=10)

        self.prompt_label.pack(side='left')
        self.property_entry.pack(side ='right')        

        self.calc_button = tkinter.Button(self.bottom_frame, \
                                          text = 'Calculate', \
                                          command = self.calculate)
        self.quit_button = tkinter.Button(self.bottom_frame, \
                                          text = 'Quit', \
                                          command = self.main_window.destroy)

        self.value = tkinter.StringVar()

        self.calc_button.pack(side='right')
        self.quit_button.pack(side='right')

        self.assess_label= tkinter.Label(self.mid_frame, \
                                        text='Assessment Value: ')

        self.assess_label.pack(side='left')

        self.value_label = tkinter.Label(self.mid_frame, \
                                         textvariable=self.value)

        self.value_label.pack(side='right')

        self.prop_label= tkinter.Label(self.third_frame, \
                                        text='Property Tax: ')

        self.prop_label.pack(side='left')

        self.propTax_label = tkinter.Label(self.mid_frame, \
                                         textvariable=self.value)

        self.propTax_label.pack(side='right')

        self.top_frame.pack()
        self.mid_frame.pack()
        self.third_frame.pack()
        self.bottom_frame.pack()

        tkinter.mainloop()

    def calculate(self):

        propVal = float(self.property_entry.get())

        assessVal = str(format(float(((.6)*propVal)), '.2f'))

        self.value.set(assessVal)

    def taxCalculate(self):

        propVal = float(self.property_entry.get())

        assessVal = str(format(float(((.6)*propVal)), '.2f'))

        assessTax = str(format(float(((.64)*assessVal)), '.2f'))

        self.value.set(assessTax)

my_gui = PropertyTaxGUI()

A:

def __init__(self):
    ...
    self.calc_button = tkinter.Button(self.bottom_frame, \
                                              text = 'Calculate', \
                                              command = self.calc_button_event)
    ...

def calc_button_event(self):
    self.taxCalculate()
    self.calculate()

also change the line in taxCalculate from:
assessVal = str(format(float(((.6)*propVal)), '.2f'))

to:
assessVal = propVal*0.6

