How do I control file opening with Tkinter buttons?

Question

I want a file to open on a button press within my tkinter gui. However, the sound file plays when my program runs (as in straight away) and doesn't work when the button is pressed. Here is my code:

    ####Imports
    import os
    import sys
    from tkinter import *

    ####definitions
    def blackobj ():
        from os import startfile
        startfile ('simon_objection.mp3')

    ####Window
    mGui = Tk()
    mGui.geometry ('1280x720+100+50')
    mGui.title ('Gui App')
    mGui.configure(background='blue')

    ####Labels
    #Title
    wlabel = Label(text = "Welcome to the Ace Attorney Soundboard!", font = 'georgia',fg  ='white', bg = 'blue').place(x=0,y=0)
    objectionheader = Label (text = 'Objections:', font = 'georgia', fg = 'white', bg = 'blue',).place (x=0,y=45)

    ####Buttons
    objblackquill = Button (mGui, text = 'Blackquill', font = 'georgia', command =blackobj()).place (x=0,y=75)

    mGui.mainloop()

Have I made a mistake in my code or do I need to add something else to get the sound to work when the button is pressed and not when the script runs?

Thanks

Answer 1

objblackquill = Button (mGui, text = 'Blackquill', font = 'georgia', command =blackobj()).place (x=0,y=75)

Your problem is with the above line. When Python reads your code, it sees blackobj() , which it interprets as a valid function call. So, it executes it.

---

To fix the problem, you could use a lambda to "hide" the call to blackobj inside a function of its own:

objblackquill = Button (..., command=lambda: blackobj()).place (x=0,y=75)

However, since you are not passing blackobj any arguments, an even better solution is to just remove the parenthesis:

objblackquill = Button (..., command=blackobj).place (x=0,y=75)

---

Also, tkinter.<widget>.place always returns None and therefore should be called on its own line.

In other words, every line written like this:

wlabel = Label(...).place(x=0,y=0)

should be written like this instead:

wlabel = Label(...)
wlabel.place(x=0,y=0)