Tkinter create RadioButtons from dictionary issue

Question

Here is my problem: I've made a tkinter program which calculate the cost of a creation my wife make. She sews accessories. So far my program is working pretty well. I search in a JSON file if this fabric already exist in some kind of catalogue.

When my catalogue have the same fabric name, I want to make a popup window with radiobutton. By checking the correct radiobutton I chose the correct fabric. So I've extracted the dictionary of same fabric names, when I type the fabric name entry and then click on enter, it sends the dictionnary to the popup window which creates radiobutton in a for loop.

The problem comes here, my radiobutton are correctly made but impossible to get there state nor which button is checked...

First, here's the dictionary :

{"Tissu 1": {"Type": "Tissu", "Matière": "coton", "Prix du coupon": "8",
    "Laise du coupon (cm)": "150",
    "Prix au mètre (€)": 8.0,
    "Fournisseur": "lol"},
"Tissu 2": {"Type": "Tissu", "Matière": "molleton", "Prix du coupon": "10",
    "Laise du coupon (cm)": "150", 
    "Prix au mètre (€)": 10.0, 
    "Fournisseur": "lol"},
"Tissu 3": {"Type": "Tissu", "Matière": "coton", "Prix du coupon": "12", 
    "Laise du coupon (cm)": "150", 
    "Prix au mètre (€)": 12.0, 
    "Fournisseur": "mol"}}

Here's my code:

First there is the main class:

    class ProgramCalcul(tk.Tk):

        def __init__(self, *args, **kwargs):

        self.frames = {}

            for F in (StartPage, CalculTissuPage, CalculMercPage):

                frame = F(container, self)

                self.frames[F] = frame

                frame.grid(row = 0, column = 0, sticky = "nsew")

            self.show_frameSP(StartPage)

        def show_frameSP(self, cont):
            frame = self.frames[cont]

            frame.tkraise()

Then I have a class for each other calcul page

Here is the fabric calcul page (I've removed some entries and other widgets for legibility and because they work fine):

class CalculTissuPage(tk.Frame):
    def __init__(self, parent, controller):

        tk.Frame.__init__(self, parent)

        tissuType = tk.StringVar()
        TissuNameEntry = tk.Entry(self, textvariable = tissuType, width = 50)
        TissuNameEntry.grid(row = 2, padx = 20, pady = 5, sticky = "ew")

        def keyPress(arg):
            checkCatalogueTissu(TissuNameEntry.get())
        TissuNameEntry.bind('<Return>', keyPress)

        def checkCatalogueTissu(txt):

            tmpDict = {}

            with open("catalogue tissu.json") as json_file:
                data = json.load(json_file)

                dictLen = len(data)
                for i in range(1, dictLen+1):

                    if "Tissu {}".format(i) not in data:
                        pass

                    else:
                        if data["Tissu {}".format(i)]["Matière"] == txt:

                            tmpDict["Tissu {}".format(i)] = data["Tissu {}".format(i)]

            popupRadio(tmpDict)

        def setText(txtPrix, txtFournisseur, txtLaise, txtLong):
            couponPrixEntry.delete(0,tk.END)
            couponPrixEntry.insert(0,txtPrix)
            fournisseurEntry.delete(0, tk.END)
            fournisseurEntry.insert(0, txtFournisseur)
            laiseDimEntry.delete(0, tk.END)
            laiseDimEntry.insert(0, txtLaise)
            longCouponEntry.delete(0,tk.END)
            longCouponEntry.insert(0,txtLong)

And finally the function which create the popup in which appear the radiobuttons:

def popupRadio(tmpDict):

    popup = tk.Toplevel()
    popup.wm_title("!")

    popupVar = tk.IntVar()

    def checkState(popupVar):
        print(popupVar.get())


    for (key, val) in tmpDict.items():

        tk.Radiobutton(popup, text = key, variable = popupVar, value = val, command = checkState(popupVar)).grid()
        print(key, popupVar.get())

    chk = ttk.Button(popup, text = "Select this", command = checkState(popupVar))
    chk.grid()

    popup.mainloop()

When I run it, the checkState() method seems to run automatically and then the chk button doesn't do anything... I can check the radiobuttons but nothing happens (even if I pass the command=chechState in the radiobutton settings. I want to get which button is checked to use this value in my setText() method further.

for the moment, here is the output the print() send in my console :

0
Tissu 1 0
0
Tissu 3 0
0

So here I am, it's been 2 days since I've tried evrything I found on the web but nothing...

A little help would be very appreciated

PS: sorry if my english is not perfect :)