ttk Styling doesn't work inside functions

Question

I have some ttk buttons but they're inside a function and whenever I try to style it it doesn't work but when I create a new file and use same lines but without putting it inside functions it works just fine. Here's the snippet of code.

def function():
    if Something == Another thing: 
        r = Tk() # Opens new window
        r.title('Lorem ipsum')
        s = ttk.Style()
        s.configure('TButton', font=('Helvetica', 18))
        Button = ttk.Button(r, text = "lorem ipsum dolor sit amet",command = lorem ipsum,style="TButton")
        Label = ttk.Label(r, text = "Get total Stores Values and quantities")
        Label.place(relx = 0.2, rely= 0.4,anchor=CENTER)
        Button.place(relx = 0.5, rely= 0.4 ,width= 500 ,height = 50  ,anchor=CENTER)

Thanks and hope it's clear enough.

Answer 1

Since there are multiple Tk() instances, you need to specify which instance the style belongs to:

from tkinter import *
from tkinter import ttk

def function():
    if True:
        r = Tk() # Opens new window
        r.geometry('600x400')
        r.title('Lorem ipsum')
        s = ttk.Style(r) # should specify which Tk instance
        s.configure('TButton', font=('Helvetica', 18))
        Button = ttk.Button(r, text="lorem ipsum dolor sit amet", style="TButton")
        Label = ttk.Label(r, text="Get total Stores Values and quantities")
        Label.place(relx=0.5, rely=0.4, anchor=CENTER)
        Button.place(relx=0.5, rely=0.6, width=500, height=50, anchor=CENTER)

root = Tk()
function()
root.mainloop()

Note that you used TButton as the style name which affects all the ttk.Button() (actually you can remove style="TButton"). Better to use other name like Custom.TButton if you want to apply the style to particular widgets only.

Avoid using multiple Tk() instances. Use Toplevel() if you can.