from tkinter import Canvas, Tk, Frame
import locale

# use German locale to make it crash
# - might have to use "deu_deu" on Windows
#locale.setlocale(locale.LC_ALL, 'deu_deu')
# - on Ubuntu, use "locale -a" in a terminal to find available locales
locale.setlocale(locale.LC_ALL, 'de_DE.utf8')

# use C locale to make it work:
#locale.setlocale(locale.LC_NUMERIC, 'C')

print("locale =", locale.getlocale(locale.LC_NUMERIC))

master = Tk()
master.title("Test")

w = 10.0 # the evil float width

frame = Frame(master)
Canvas(master=frame, width=w, height=2, borderwidth=4)