I've a problem with the code that I have written. When I insert the variable calendar2019 into the tkinter label LabelCalen it does not show up in the window root4, and the window root4 is not created at all.
import calendar
import tkinter as tk
def CalScr():
calendar2019 = calendar.calendar(2019)#creating calender variable
root4 = tk.Tk()
labelCalen= tk.Label(root4, text = calendar2019, )
root4.mainloop
CalScr()
the calender should be printed out in the label LabelCalen