How to automatically pause on cv2.waitkey without pressing Keyboard

I have an urgent question and I hope someone will help me. Is there any way to auto pause my program when it detected.

Here is my example:

if tag1 in a_str:
 cv2.imshow("GUI", tag1)
 cv2.waitKey(100)
 continue

This code is being detect but it will keep on blinking, I would like just pause the cv2.waitkey at there once detected. I have research about this type of question, but mostly people are using "Keyboard" or "ord("")" to control which not what i want, is there any solution for auto pause?