我目前正在做我大学最后一年的项目,我被困在我认为是线程的问题。我希望能够多次运行我的方法,但每次运行它都应该用新值更新一个变量。我正在查询一个API以获取userID,然后通过将其设置为全局变量将其传递到我的main方法中。你知道吗
def setup():
try:
global gun_cascade, camera, frameRate, property_id, length, firstFrame, framecount,i,increment,start_Time,end_Time,statusCopy,userID
gun_cascade = cv2.CascadeClassifier('cascade.xml')
camera = cv2.VideoCapture('gun.mp4')
if camera.isOpened() == False:
print("Can't open video, isOpened is empty exiting now.")
exit(0)
frameRate = camera.get(5)
property_id = int(cv2.CAP_PROP_FRAME_COUNT)
length = int(cv2.VideoCapture.get(camera, property_id))
firstFrame = None
count = 0
gun_exist = False
increment = 0
start_Time = 0
end_Time = 0
i = 0
except Exception as e:
print(e)
exit(0)
上面我将userID设置为global
def decision():
setup()
user_object = listener.userIdListner()
tokenId = user_object.token
status = user_object.status
if user_object.status == "ON":
#status=statusCopy[:]
#aux = copy.deepcopy(matriz)
global statusCopy
statusCopy = copy.deepcopy(tokenId)
print("About to run mainscrt"+statusCopy)
#print(type(userID))
print(type(user_object))
post_object = listener.mainNullPostMethod()
post_object.null
print(post_object.null)
#opening a a new thread
Thread(target = main).start()
#post_object = listener.mainNullPostMethod()
#post_object.null
#print(post_object.null)
else:
print ("Program failed to run")
在这里,我查询我的API来获取用户id和状态,无论是开还是关。目前情况还不错。但是问题是,如果这个方法正在运行,并且想用一个新的userID再次运行它,那么它会一直工作到'while'摄影机.isopend():“当我走到这一步时,我没有发现任何错误
def main():
#printing out the userid to see if it's been changed
userID = statusCopy
print("The current userID is "+userID)
while isOpened:
framecount =0
framecount += 1
frameId = camera.get(1) #current frame number
(grabbed, frame) = camera.read()
if not grabbed:
break
# resize the frame, convert it to grayscale, and blur it
frame = imutils.resize(frame, width=500)
gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
#gray = cv2.GaussianBlur(gray, (21, 21), 0)
#gray = cv2.dilate(gray, None, iterations=2)
#stuff to try in the future
#scaleFactor=1.1, minNeighbors=5, minSize=(30, 30), flags=cv2.CASCADE_SCALE_IMAGE, outputRejectLevels = True
gun = gun_cascade.detectMultiScale(gray, 3,5)
for (x,y,w,h) in gun:
randID = uuid.uuid4().hex
frame = cv2.rectangle(frame,(x,y),(x+w,y+h),(255,0,0),2)
roi_gray = gray[y:y+h, x:x+w]
roi_color = frame[y:y+h, x:x+w]
rects = gun[0]
neighbours = gun[0]
weights = gun[0]
if (frameId % math.floor(frameRate) == 1):
cv2.putText(frame, datetime.datetime.now().strftime("%A %d %B %Y %I:%M:%S%p"),(10, frame.shape[0] - 10), cv2.FONT_HERSHEY_SIMPLEX, 0.35, (255, 165, 0), 1)
cv2.imwrite('bin/' + userID+'-'+randID + '.jpg', frame)
if userID == "NULL":
print("failed due to user null")
break
print("working on pushing images to s3"+userID)
s3.uploadDirectory("bin/", "open-gun-recordings",userID)
picURL = "s3bucket.com/users/screenshots/"+userID+'/'+userID+'-'+randID+'.jpg'
text.fire(picURL)
cv2.imshow("Security Feed", frame)
key = cv2.waitKey(1) & 0xFF
camera.release()
cv2.destroyAllWindows()
在上面,我希望能够同时运行此方法的多个实例,并为每个实例使用不同的userId。你知道吗
if __name__ == '__main__':
#mainNullPostMethod()
#runDecision()
while True:
time.sleep(5)
decision()
任何帮助和建议都将不胜感激。我不是python的高手,如果这是个愚蠢的问题,我很抱歉
首先不要使用全局变量,因为当从多个函数(在您的例子中是多个线程)as described in this answer更改时,很难跟踪全局变量。你知道吗
我看到的问题是在
main
函数中初始化userID
的问题,这个函数用于生成线程,问题是即使在main
中初始化userID = statusCopy
,即使在decision
中使用statusCopy = copy.deepcopy(tokenId)
进行深度复制,它仍然会被任何并发的决策调用全局覆盖。你知道吗让我们设想一下,第一次调用
decision
,初始化userID
,然后为main
生成一个线程,该线程利用了userID
。现在我不确定执行main
需要多长时间,但假设您使用sleep
等待5秒钟,然后再次执行整个操作(第一个线程仍在运行)。现在您基本上更改了userID
,第二次执行整个函数链,第一个线程开始使用修改后的userID
,根据定义,这已经是一种不好的做法,因为您希望在第一个线程中使用特定的userID
信息。我建议您将deepcopy传递给线程,并在main
中初始化本地userID
,这样它就不会被并发线程更改。你知道吗另外,我不确定您是否希望执行
while True
并每5秒生成一次线程,也许您也应该在那里设置一个限制。你知道吗相关问题 更多 >
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