pycharm调用摄像头方面的问题

代码如下:
import cv2
def CatchPICFromVideo(catch_num):# catch_num=400
face_cascade = cv2.CascadeClassifier(cv2.data.haarcascades+"haarcascade_frontalface_default.xml")
camera = cv2.VideoCapture(0, cv2.CAP_DSHOW)
num = 0
while True:
ret, frame = camera.read()
gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
faces = face_cascade.detectMultiScale(gray, 1.1, 5)
for (x, y, w, h) in faces:
img_name = "imgs/yes/" + str(num) + ".jpg"
image = frame[y:y + h, x:x + w]
print(img_name)

        # 将图片处理成固定大小
        img_resize2 = cv2.resize(image, dsize=(200,200))

        cv2.imwrite(img_name, image)
        num += 1
        if num > catch_num:
            break

        # 画出矩形框圈出人脸
        cv2.rectangle(frame, (x, y), (x + w, y + h), (255, 0, 0), 2)

        # 显示捕捉了多少张人脸
        font = cv2.FONT_HERSHEY_SIMPLEX
        cv2.putText(frame, f'num:{str(num)}', (x + 30, y + 38), font, 1, (255, 0, 255), 4)
    if num > catch_num:
        break

        # 显示图像
    cv2.imshow('camera', frame)
    if cv2.waitKey(1) & 0xFF == ord('q'):
        break
camera.release()
cv2.destroyAllWindows()

CatchPICFromVideo()

少了一个参数：

CatchPICFromVideo(catch_num=400)