我遇到的问题是没有足够的值来解包（预期值为3，实际值为2）

Question

我得到了错误enter link description here（完整代码的链接）

[Running] python -u "c:\Users\prate\Desktop\Python\Driving-using-motion-recogniton-master\main.py"
Traceback (most recent call last):
File "c:\Users\prate\Desktop\Python\Driving-using-motion-recogniton-master\main.py", line 31, in
im2,contours,hierarchy=cv2.findContours(skinMask,cv2.RETR_TREE,cv2.CHAIN_APPROX_SIMPLE)#fit contours to hand regions
ValueError: not enough values to unpack (expected 3, got 2)
[ WARN:0] terminating async callback

[Done] exited with code=1 in 2.458 seconds

代码：

import cv2
import numpy as np
import math
import pyvjoy
from controls import xAxis, yAxis,Brake,j,reCentre

cap = cv2.VideoCapture(0)
Dir="-->"

while(1):

    _,img=cap.read()
    im=img
    img=img[150:450,80:500] #Define RegionOfInterest
    im=cv2.rectangle(im,(500,150),(80,450),(0,255,0),2)

    lower=np.array([0,20,150]) #HSV ranges for skin color
    upper=np.array([20,255,255])

    converted=cv2.cvtColor(img,cv2.COLOR_BGR2HSV) #convert BGR image to HSV image
    skinMask=cv2.inRange(converted,lower,upper) 
    kernel = cv2.getStructuringElement(cv2.MORPH_ELLIPSE, (7, 7))
    skinMask=cv2.morphologyEx(skinMask,cv2.MORPH_CLOSE,kernel)
    skinMask = cv2.dilate(skinMask, kernel, iterations = 4)
    skinMask = cv2.GaussianBlur(skinMask, (7,7), 0)
    skin=cv2.bitwise_and(img,img,mask=skinMask)
    im2,contours,hierarchy=cv2.findContours(skinMask,cv2.RETR_TREE,cv2.CHAIN_APPROX_SIMPLE)#fit contours to hand regions

    try:

        cnt=max(contours,key=lambda x:cv2.contourArea(x))
        for ind,ct in enumerate(contours):#Iterate over all contours in frame
            M=cv2.moments(contours[ind])
            area=int(M["m00"])
            if area in range(6000,13000):#Ignore other contours that are not of hands 
                m1=cv2.moments(contours[0])
                m2=cv2.moments(contours[1])
                x1=int(m1["m10"]/m1["m00"])
                y1=int(m1["m01"]/m1["m00"])
                x2=int(m2["m10"]/m2["m00"])
                y2=int(m2["m01"]/m2["m00"])
                slope=math.tan(((y2-y1)/(x2-x1)))*100#convert the slope into %
                slope=round(slope,2)

                if slope>0:
                    Dir="<--"
                else:
                    Dir="-->"

                distance=math.sqrt(((x2-x1)**2) + ((y2-y1)**2))
                distance=round((distance/300)*100,2)#convert distance from 0 - 300 into %

                if(distance>100):#limit distance to 100
                    distance=100
                if slope>100:#limit angle to 100
                    slope=100
                elif slope< -100:
                    slope=-100

                cv2.line(im,(x1,y1),(x2,y2),(100,255,0),5)#plot line between centres of two hands
                cv2.putText(im,"Turning:"+Dir+str(slope)+"deg",(50,50),cv2.FONT_HERSHEY_SIMPLEX,0.5,(255,255,255),2)
                cv2.putText(im,"Acceleration:"+(str(distance)),(50,150),cv2.FONT_HERSHEY_SIMPLEX,0.5,(0,255,0),2)
                xAxis(slope)#set xAxis on Joystick to the slope %
                yAxis(distance)#set yAxis on Joystick to speed %

            else:
                if area>13000 and len(contours)==1:#If area is of two hands joined
                    cv2.putText(im,"BRAKE",(50,50),cv2.FONT_HERSHEY_SIMPLEX,1,(0,0,255),4)
                    Brake()

    except ValueError:#If hands are out of the frame
        reCentre()

    except:
        pass

    cv2.imshow('main cam',im)
    cv2.imshow('segment',skin)
    if cv2.waitKey(1) & 0xFF == ord('q'):
        break

cv2.waitKey(0)
cv2.destroyAllWindows()