Python uses matplotlib to implement a method of drawing a rectangle in a coordinate system

This example describes how Python uses matplotlib to implement a rectangle in a coordinate system. Share to everyone for your reference. The implementation method is as follows:

Import Matplotlib.pyplot as Pltfrom matplotlib.patches import Rectangleclass Annotate (object):  def __init__ (self):    self.ax = PLT.GCA ()    self.rect = Rectangle ((0,0), 1, 1)    self.x0 = none    self.y0 = none    self.x1 = none
  self.y1 = None    self.ax.add_patch (self.rect)    self.ax.figure.canvas.mpl_connect (' button_press_event ', self.on_press)    self.ax.figure.canvas.mpl_connect (' button_release_event ', self.on_release)  def on_press ( Self, event):    print ' press '    self.x0 = event.xdata    self.y0 = Event.ydata  def on_release (self, event ):    print ' release '    self.x1 = event.xdata    self.y1 = Event.ydata    self.rect.set_width (self.x1- self.x0)    self.rect.set_height (self.y1-self.y0)    self.rect.set_xy ((self.x0, self.y0))    Self.ax.figure.canvas.draw () A = Annotate () plt.show ()

As shown in the following:

Hopefully this article will help you with Python programming.

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