[Tkinter] Extrakt a Variable from a closed tkinter window

[hWp]

Well, when I am doing it like this, it worked

from tkinter.filedialog import askopenfilename
import tkinter
import pandas as pd
import matplotlib.pyplot as plt
 
master = tkinter.Tk()
master.title("Sheetauswahl")

Filename = askopenfilename(filetypes = (("ExcelFiles","*.xlsm *.xlsx *.xls"),("all files","*.*")),title='Jetzt wähl endlich die Kagg-Datei')
xl = pd.ExcelFile(Filename)
print(xl.sheet_names)
 
# Add a grid
mainframe = tkinter.Frame(master)
mainframe.grid(column=0,row=0, sticky=(tkinter.N,tkinter.W,tkinter.E,tkinter.S) )
mainframe.columnconfigure(0, weight = 2)
mainframe.rowconfigure(0, weight = 2)
mainframe.pack(pady = 100, padx = 100)

def Quit():
    return master.destroy
 
button = tkinter.Button(mainframe, 
                     text="Auswahl", fg="red",
                     command = Quit())


# Create a Tkinter variable
tkvar = tkinter.StringVar(master)

 
#Convert xl_SheetNameList into Dictionary
dictOfxl = dict.fromkeys(xl.sheet_names , 1)
 
# Dictionary with options
choices = dictOfxl
tkvar.set(xl.sheet_names[0]) # set first xl_Sheet as default option
 
popupMenu = tkinter.OptionMenu(mainframe, tkvar, *choices)
tkinter.Label(mainframe, text="Choose a sheet").grid(row = 1, column = 1)
popupMenu.grid(row = 2, column =1)
button.grid(row = 3, column = 1)
 
# on change dropdown value
def change_dropdown(*args):
    return tkvar.get()
    
# link function to change dropdown
tkvar.trace('w', change_dropdown)

master.mainloop()

sheet = tkvar.get()
print('Der Name ist',sheet)
df = pd.read_excel(Filename, sheet_name=sheet)
print(df)

I don't know if I explained it wrong, but this should be faster to solve...hätte es auch in deutsch erklären können, dass ich einfach nur nach ner Excel Sheet Auswahl Tkinter weghaben wollte und dann mein Programm nach der Mainloop bzw. dem Tkinter weiterlaufen soll mit dem Ausgewählten Tabllenblatt aus dem Dropdown ... wieso soll das nicht gehen?


Best wishes