我怎样才能只打印文件中的一行

Question

# ***Main.py***
import os
import cv2
import numpy as np
import face_recognition
from datetime import datetime

path = 'MainImages' // containes simple images
images = []
classNames = []
myList = os.listdir(path)

for cl in myList:
    curImg = cv2.imread(f'{path}/{cl}')
    images.append(curImg)
    classNames.append(os.path.splitext(cl)[0])

def findEncodings(images):
    encodeList = []
    for img in images:
        img = cv2.cvtColor(img, cv2.COLOR_BGR2RGB)
        encode = face_recognition.face_encodings(img)[0]
        encodeList.append(encode)

    return encodeList

def markAttendance(name):
    with open('Attendance.csv','r+') as f:
        myDataList = f.readlines()
        nameList = []
        for line in myDataList:
            entry = line.split(',')
            nameList.append(entry[0])
            if name not in nameList:
                now = datetime.now()
                dtString = now.strftime('%H:%M:%S')
                f.writelines(f'\n{name},{dtString}')

encodeListKnown = findEncodings(images)
print('Encoding Complete')

cap = cv2.VideoCapture(0)

while True:
    success, img = cap.read()
    imgS = cv2.resize(img, (0, 0), None, 0.25, 0.25)
    imgS = cv2.cvtColor(imgS, cv2.COLOR_BGR2RGB)

    facesCurFrame = face_recognition.face_locations(imgS)
    encodesCurFrame = face_recognition.face_encodings(imgS, facesCurFrame)

    for encodeFace, faceLoc in zip(encodesCurFrame, facesCurFrame):
        matches = face_recognition.compare_faces(encodeListKnown, encodeFace)
        faceDis = face_recognition.face_distance(encodeListKnown, encodeFace)
        matchIndex = np.argmin(faceDis)

        if matches[matchIndex]:
            name = classNames[matchIndex].upper()
            y1, x2, y2, x1 = faceLoc
            y1, x2, y2, x1 = y1*4, x2*4, y2*4, x1*4
            cv2.rectangle(img, (x1, y1), (x2, y2), (0, 255, 0), 2)
            cv2.rectangle(img, (x1, y2-35), (x2, y2), (0, 255, 0), cv2.FILLED)
            cv2.putText(img, name, (x1+6, y2-6), cv2.FONT_HERSHEY_COMPLEX, 1, (255, 255, 255), 2)
            markAttendance(name)

    cv2.imshow('Webcam', img)
    cv2.waitKey(1)

请有人能弄清楚，当我在面部摄像头中显示一张脸时，它正在Attendance.csv 中写入出勤率，但当我在相机中显示时，它会多次写入同一行。请有人解决这个问题，我正在尝试，但它不起作用。我是初学者请帮忙。

我很努力，但没有成功。我多次期待它能起作用。

Answer 1

我无法运行代码，但我认为你的缩进有误

markAttendance

，

您在

if

循环中使用

for

，它可能会在每个循环中写入新行。

您应该首先运行所有

for

循环来获取所有数据，然后运行

if

来检查名称。

def markAttendance(name):

    with open('Attendance.csv', 'r+') as f:

        # --- loop ---

        nameList = []

        for line in f:
            entry = line.split(',')
            nameList.append(entry[0])

        # --- after loop --- 

        if name not in nameList:
            dt = datetime.now().strftime('%H:%M:%S')
            f.writelines(f'\n{name},{dt}')