[python plt画矩形]

import matplotlib.pyplot as plt
import numpy as np
 
def rec(ax, b1, b2, show_point=True, show_loc=True):
    xmin,xmax = min(b1[0], b2[0]), max(b1[0], b2[0])
    ymin,ymax = min(b1[1], b2[1]), max(b1[1], b2[1])
    
    # 1
    # ax.arrow(xmin, ymin, xmax-xmin,0)
    # ax.arrow(xmin, ymin, 0,ymax-ymin)
    # ax.arrow(xmax, ymax, xmin-xmax, 0)
    # ax.arrow(xmax, ymax, 0, ymin- ymax)
    
    # 2
    ax.hlines([ymin, ymax],[xmin, xmin], [xmax, xmax], colors='black')
    ax.vlines([xmin, xmax],[ymin, ymin], [ymax, ymax], colors='black')
    
    xs,ys = np.meshgrid([xmin, xmax],[ymin,ymax])
    
    if show_point:
        ax.scatter(xs,ys)
        
    if show_loc:
        for x,y in zip(xs.flatten(),ys.flatten()):
            ax.text(x,y,f'({x}, {y})', fontdict={'c':'r'})
 
# [x,y],[x,y]
rec(plt, [1,2], [3,4], False, False)
rec(plt, [6,9], [4,9])
plt.show()