I got stuck with this error after running resize function line:

import cv2
import numpy as np
import matplotlib.pyplot as pltnet = cv2.dnn.readNetFromDarknet('yolov3_custom.cfg', 'yolov3_custom_last.weights')cap = cv2.VideoCapture(0)while 1:_, img = cap.read()img = cv2.resize(img,(1280,720))hight,width,_ = img.shapeblob = cv2.dnn.blobFromImage(img, 1/255,(416,416), (0,0,0), swapRB = True,crop= False)

This error is because of no frames is getting captured.

Please try

cap = cv2.VideoCapture(1)