如何在函数外使用此变量？

Question

Three_Series = ["3S BLACK STOCK RIMS.png"]

def SelectedCarFunction(event=None):
    Model = Var2.get()
    Colour = Var3.get()
    Wheels = Var4.get()

变量Model，Colour和Wheels完全检索，因为它们应该是

if Model == "3 Series" and Colour == "Black" and Wheels == "Stock":
    VarSC = Three_Series[0]
    print(VarSC)

我将print(VarSC)放在此处进行测试，看看它是否会打印"3S BLACK STOCK RIMS.png"并且确实

   return VarSC

VarSC = StringVar()

DisplayFrame.grid_propagate(False)

print(VarSC)

然而，现在当我print(VarSC)查看它是否打印出与之前相同的值时，相反它打印出PY_VAR9

CarImage = PhotoImage(file=VarSC)

这里我想将文件分配给VarSC，即我希望VarSC等于"3S BLACK STOCK RIMS.png"，但它不是

CarImageLabel = Label(DisplayFrame, image=CarImage)
CarImageLabel.grid(row=0, column=0)

root.mainloop()

以下是整个代码：

Three_Series = ["3S BLACK STOCK RIMS.png"]

def SelectedCarFunction(event=None):
    Model = Var2.get()
    Colour = Var3.get()
    Wheels = Var4.get()

    if Model == "3 Series" and Colour == "Black" and Wheels == "Stock":
    VarSC = Three_Series[0]
    print(VarSC)
    return VarSC

VarSC = StringVar()

DisplayFrame.grid_propagate(False)

print(VarSC)
CarImage = PhotoImage(file=VarSC)
CarImageLabel = Label(DisplayFrame, image=CarImage)
CarImageLabel.grid(row=0, column=0)

root.mainloop()