A string that I have put on a frame through cv2.putText() in opencv , how can I backspace or delete the last character from that string?

Question

for i in range(40): if i == letter_index: light=True else: light=False letter(i,keys_set_1[i], light) cv2.putText(board,text,(10,100),font,4,0,3)

#here text is the st