Practice with opencv
import cv2
waitKey(arg1) desc: wait before close arg1: int
imread(arg1) desc: read photo arg1: file path
imshow(arg1, arg2) desc: show photo arg1: window name arg2: imread variable
VideoCapture(arg1) desc: read video arg1: file path arg1: 0 is webcam arg1: numbers after 0 order of cams connected
read() desc: reads video frame by frame desc: returns if frame was successfully read
imshow(arg1, arg2) desc: show video arg1: window name arg2: frame
0xFF==ord('d') if d key is press
release() destroyAllWindows()