MouseEvents.py

import cv2
import numpy as np

# Create a black image and a window
windowName = 'Drawing'
img = np.zeros((512, 512, 3), np.uint8)
cv2.namedWindow(windowName)

# mouse callback function
def draw_circle(event, x, y, flags, param):
    if event == cv2.EVENT_LBUTTONDBLCLK:
        cv2.circle(img, (x, y), 40, (0, 255, 0), -1)
    if event == cv2.EVENT_MBUTTONDOWN:
        cv2.circle(img, (x, y), 20, (0, 0, 255), -1)
    if event == cv2.EVENT_LBUTTONDOWN:
        cv2.circle(img, (x, y), 30, (255, 0, ), -1)

# bind the callback function to window
cv2.setMouseCallback(windowName, draw_circle)

def main():
    
    while(True):
        cv2.imshow(windowName, img)
        if cv2.waitKey(20) == 27:
            break
        
    cv2.destroyAllWindows()
        
if __name__ == "__main__":
    main()