python matplotlibのツールバー使用時クリックした点の座標を取得したいがglobal変数にしない方法がありますか

import tkinter as tk
import tkinter.filedialog
from tkinter import ttk
import matplotlib.pyplot as plt
from matplotlib.backends.backend_tkagg \
    import FigureCanvasTkAgg, NavigationToolbar2Tk
from matplotlib.backend_bases import (_Mode)

def main():
    RC = ReadCSV()
    datCSV, datNum = RC.set_data()
    
    PA = PlotAll(datCSV, datNum)
    PA.plot()
    
    print("クリックした点の座標は、X座標：", PUx, "、 Y座標：", PUy)
    
class ReadCSV:
# 実際はCSVデータの読込み
# 検討用データを入力しておく
    def __init__(self):
        self.datCSV = []

    def set_data(self):
        self.datCSV = [(0.000, 1.000), (0.007,-0.468), (0.013,-0.438), \
            (0.020, 0.819), (0.027,-0.383), (0.033,-0.358), (0.040, 0.670), \
            (0.047,-0.314), (0.053,-0.293), (0.060, 0.549), (0.067,-0.257), \
            (0.073,-0.240), (0.080, 0.449), (0.087,-0.210), (0.093,-0.197), \
            (0.100, 0.368), (0.107,-0.172), (0.113,-0.160), (0.120, 0.301), \
            (0.127,-0.141), (0.133,-0.132), (0.140, 0.247), (0.147,-0.115), \
            (0.153,-0.108), (0.160, 0.202), (0.167,-0.094), (0.173,-0.088), \
            (0.180, 0.165), (0.187,-0.077), (0.193,-0.072), (0.200, 0.135)]
        self.datCSV = tuple(self.datCSV)
        self.datNum = 31
        return self.datCSV, self.datNum

class PlotAll:
# 全データをグラフに表示
# クリックした点の座標を取得する
    def __init__(self, dC, dN):
        self.datCSV   = dC
        self.datNum   = dN
        self.plot_x = []
        self.plot_y = []
        
    def setData(self):
        for n in range(self.datNum):
            self.plot_x.append(self.datCSV[n][0])
            self.plot_y.append(self.datCSV[n][1])

    def plot(self):
        self.setData()

        self.fig, self.ax = plt.subplots()
        self.ax.plot(self.plot_x, self.plot_y)

        self.win = tk.Tk()
        self.win.withdraw()
        self.win.protocol('WM_DELETE_WINDOW', lambda: self.clickX(self.win))
    
        self.canvas = FigureCanvasTkAgg(self.fig, master=self.win)
        self.canvas.draw()
        self.canvas.get_tk_widget().pack()
        self.toolbar = \
                NavigationToolbarPlotAll(self.fig, self.win, self.canvas)

        self.win.update()
        self.win.deiconify()
        self.win.mainloop()

    def clickX(self, win):
        self.win = win
        global PUx
        global PUy
        PUx = 0
        PUy = 0
        self.destroyWinAll(self.win)

    def destroyWinAll(self, win):
        self.win = win
        self.win.quit()
        self.win.destroy()

class NavigationToolbarPlotAll(NavigationToolbar2Tk):
# matplotlibのツールバーを利用
# panかzoomの時はクリックを無効にする
# ボタンが押されていなければクリックした点の座標を取得する
    toolitems = [t for t in NavigationToolbar2Tk.toolitems \
                    if t[0] in ('Home', 'Back', 'Forward', 'Pan', 'Zoom')]

    def __init__(self, fig, win, canvas):
        super().__init__(canvas, win)
        self.fig    = fig
        self.win    = win
        self.canvas = canvas
        self.pressevent_cid = \
            self.fig.canvas.mpl_connect('button_press_event', \
                lambda event: self.clickSP(event, self.win))

    def pan(self):
        super().pan()
        if self.mode == _Mode.PAN:
            self.fig.canvas.mpl_disconnect(self.pressevent_cid)
        else:
            self.fig.canvas.mpl_connect("button_press_event", \
                lambda event: self.clickSP(event, self.win))

    def zoom(self):
        super().zoom()
        if self.mode == _Mode.ZOOM:
            self.fig.canvas.mpl_disconnect(self.pressevent_cid)
        else:
            self.fig.canvas.mpl_connect("button_press_event", \
                lambda event: self.clickSP(event, self.win))

    def clickSP(self, event, win):
        self.win = win
        global PUx
        global PUy
        x_val, y_val = (event.xdata, event.ydata)
        PUx = x_val
        PUy = y_val
        self.destroyWinAll(self.win)

    def destroyWinAll(self, win):
        self.win = win
        self.win.quit()
        self.win.destroy()

if __name__ == "__main__":
    main()