是否可以使用python在绘图中选择数据并删除所选数据？

你好，我做了一个python文件，通过创建一个多边形，可以选择数据，然后我想删除多边形内的点。这是我的代码：

import pylab as plt
import numpy as np
from shapely.geometry import Point
from shapely.geometry.polygon import Polygon
#from matplotlib.widgets import Button

a = np.array([1,2,3,5,7])
b = np.array([1,6,5,7,9])
plt.plot(a,b, '.')
myList=[]

class Canvas(object):
    def __init__(self,ax):
        self.ax = ax

        # Create handle for a path of connected points
        self.path, = ax.plot([],[],'o-',lw=3)
        self.vert = []
        self.ax.set_title('LEFT: new point, MIDDLE: delete last point, RIGHT: close polygon')

        self.x = [] 
        self.y = []

        self.mouse_button = {1: self._add_point, 2: self._delete_point, 3: self._close_polygon}

    def set_location(self,event):
        if event.inaxes:
            self.x = event.xdata
            self.y = event.ydata

    def _add_point(self):
        self.vert.append((self.x,self.y))

    def _delete_point(self):
        if len(self.vert)>0:
            self.vert.pop()

    def _close_polygon(self):
        self.vert.append(self.vert[0])
        for i in range(0,a.size):
            myList.append(Point(a[i],b[i]))
        polygon = Polygon(self.vert)
        for i1 in range(0,a.size):
            if polygon.contains(myList[i1]):
                global a,b
                a = np.delete(a,i1)
                b = np.delete(b,i1)
        plt.plot(a,b, 'g.')





    def update_path(self,event):

        # If the mouse pointer is not on the canvas, ignore buttons
        if not event.inaxes: return

        # Do whichever action correspond to the mouse button clicked
        self.mouse_button[event.button]()

        x = [self.vert[k][0] for k in range(len(self.vert))]
        y = [self.vert[k][1] for k in range(len(self.vert))]
        self.path.set_data(x,y)
        plt.draw()
if __name__ == '__main__':

    fig = plt.figure(1,(8,8))
    ax = fig.add_subplot(111)
    cnv = Canvas(ax)

    plt.connect('button_press_event',cnv.update_path)
    plt.connect('motion_notify_event',cnv.set_location)

class Index(object):
    ind = 0

    def next(self, event):
        plt.draw()

    def prev(self, event):
        plt.draw()

callback = Index()


plt.show()

---

但我有两个问题：首先，我不知道为什么，但多边形内的点留在图形中。然后，多边形内的点变成绿色，而它们不在多边形外。非常感谢你的帮助

也许会有帮助？谢谢，但我现在想要的是能够删除这一点：）