Одна из вещей, которые выполняет этот нижеприведенный код, - это помещает разные идентификаторы учащихся в крошечную базу данных после проверки, присутствует ли новый идентификатор уже или нет. Код ниже -
#enroll.py
# USAGE
# python enroll.py --id S1901 --name somename --conf config/config.json
# import the necessary packages
from pyimagesearch.utils import Conf
from imutils.video import VideoStream
from tinydb import TinyDB
from tinydb import where
import face_recognition
import argparse
import imutils
import pyttsx3
import time
import cv2
import os
# construct the argument parser and parse the arguments
ap = argparse.ArgumentParser()
ap.add_argument("-i", "--id", required=True,
help="Unique student ID of the student")
ap.add_argument("-n", "--name", required=True,
help="Name of the student")
ap.add_argument("-c", "--conf", required=True,
help="Path to the input configuration file")
args = vars(ap.parse_args())
# load the configuration file
conf = Conf(args["conf"])
# initialize the database and student table objects
db = TinyDB(conf["db_path"])
studentTable = db.table("student")
# retrieve student details from the database
student = studentTable.search(where(args["id"]))
# check if an entry for the student id does *not* exist, if so, then
# enroll the student
if len(student) == 0:
# initialize the video stream and allow the camera sensor to warmup
print("[INFO] warming up camera...")
vs = VideoStream(src=0).start()
time.sleep(2.0)
# initialize the number of face detections and the total number
# of images saved to disk
faceCount = 0
total = 0
# ask the student to stand in front of the camera
print("{} please stand in front of the camera until you" \
"receive further instructions".format(args["name"]))
# initialize the status as detecting
status = "detecting"
# create the directory to store the student's data
os.makedirs(os.path.join(conf["dataset_path"], conf["class"],
args["id"]), exist_ok=True)
# loop over the frames from the video stream
while True:
# grab the frame from the threaded video stream, resize it (so
# face detection will run faster), flip it horizontally, and
# finally clone the frame (just in case we want to write the
# frame to disk later)
frame = vs.read()
frame = imutils.resize(frame, width=400)
frame = cv2.flip(frame, 1)
orig = frame.copy()
# convert the frame from from RGB (OpenCV ordering) to dlib
# ordering (RGB) and detect the (x, y)-coordinates of the
# bounding boxes corresponding to each face in the input image
rgb = cv2.cvtColor(frame, cv2.COLOR_BGR2RGB)
boxes = face_recognition.face_locations(rgb,
model=conf["detection_method"])
# loop over the face detections
for (top, right, bottom, left) in boxes:
# draw the face detections on the frame
cv2.rectangle(frame, (left, top), (right, bottom),
(0, 255, 0), 2)
# check if the total number of face detections are less
# than the threshold, if so, then skip the iteration
if faceCount < conf["n_face_detection"]:
# increment the detected face count and set the
# status as detecting face
faceCount += 1
status = "detecting"
continue
# save the frame to correct path and increment the total
# number of images saved
p = os.path.join(conf["dataset_path"], conf["class"],
args["id"], "{}.png".format(str(total).zfill(5)))
cv2.imwrite(p, orig[top:bottom, left:right])
total += 1
# set the status as saving frame
status = "saving"
# draw the status on to the frame
cv2.putText(frame, "Status: {}".format(status), (10, 20),
cv2.FONT_HERSHEY_SIMPLEX, 0.5, (255, 0, 0), 2)
# show the output frame
cv2.imshow("Frame", frame)
cv2.waitKey(1)
# if the required number of faces are saved then break out from
# the loop
if total == conf["face_count"]:
# let the student know that face enrolling is over
print("Thank you {} you are now enrolled in the {} " \
"class.".format(args["name"], conf["class"]))
break
# insert the student details into the database
studentTable.insert({args["id"]: [args["name"], "enrolled"]})
# print the total faces saved and do a bit of cleanup
print("[INFO] {} face images stored".format(total))
print("[INFO] cleaning up...")
cv2.destroyAllWindows()
vs.stop()
# otherwise, a entry for the student id exists
else:
# get the name of the student
name = student[0][args["id"]][0]
print("[INFO] {} has already already been enrolled...".format(
name))
# close the database
db.close()
ПРОБЛЕМА: Пока я запускаю этот код в первый раз, все работает нормально.
>> python3 enroll.py --id S1111 --name thor --conf config/config.json
Я получаю свой идентификатор в json файл, как показано ниже -
{"student": {"1": {"S1111": ["thor", "enrolled"]}}}
Но когда я пытаюсь ввести другой идентификатор -
python3 enroll.py --id S1112 --name hulk --conf config/config.json
, я получаю следующую ошибку -
ERROR :
Traceback (most recent call last):
File "enroll.py", line 35, in <module>
student = studentTable.search(where(args["id"]))
File "/usr/lib/python3.5/site-packages/tinydb/table.py", line 222, in search
docs = [doc for doc in self if cond(doc)]
File "/usr/lib/python3.5/site-packages/tinydb/table.py", line 222, in <listcomp>
docs = [doc for doc in self if cond(doc)]
File "/usr/lib/python3.5/site-packages/tinydb/queries.py", line 59, in __call__
return self._test(value)
File "/usr/lib/python3.5/site-packages/tinydb/queries.py", line 136, in notest
raise RuntimeError('Empty query was evaluated')
RuntimeError: Empty query was evaluated
Если я изменю имя своей таблицы с student на что-то другое, то снова он сохранит идентификатор только в первый раз, а затем выдаст ту же ошибку. Я не уверен, что здесь не так.