python列表索引超出范围如何处理？

Question

大佬们这个显示“list index out of range”（中文：列表索引超出范围）

#怎么解决？

import cv2

recognizer = cv2.face.LBPHFaceRecognizer_create()
recognizer.read("C:\work\AI\AI-picture\Face recognition\\face_trainer\\trainer.yml")
cascadePath = "C:\work\AI\AI-picture\Face recognition\haarcascade_frontalface_default.xml"
faceCascade = cv2.CascadeClassifier(cascadePath)
font = cv2.FONT_HERSHEY_SIMPLEX

idnum = 0

names = ['A', 'Bob']

cam = cv2.VideoCapture(0, cv2.CAP_DSHOW)
minW = 0.1*cam.get(3)
minH = 0.1*cam.get(4)

while True:
    ret, img = cam.read()
    gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)

    faces = faceCascade.detectMultiScale(
        gray,
        scaleFactor=1.2,
        minNeighbors=5,
        minSize=(int(minW), int(minH))
    )

    for (x, y, w, h) in faces:
        cv2.rectangle(img, (x, y), (x+w, y+h), (0, 255, 0), 2)
        idnum, confidence = recognizer.predict(gray[y:y+h, x:x+w])

        if confidence < 100:
            idnum = names[idnum]#问题出在这儿
            confidence = "{0}%".format(round(100 - confidence))
        else:
            idnum = "unknown"
            confidence = "{0}%".format(round(100 - confidence))

        cv2.putText(img, str(idnum), (x+5, y-5), font, 1, (0, 0, 255), 1)
        cv2.putText(img, str(confidence), (x+5, y+h-5), font, 1, (0, 0, 0), 1)

    cv2.imshow('camera', img)
    k = cv2.waitKey(10)
    if k == 27:
        break

cam.release()
cv2.destroyAllWindows()

Answer 1

训练人脸时的id数据大于保存的姓名数
检查采集时的图片命名格式或者训练时保存的id格式是否正确