QR code data missing in some of my QR codes

[Pedroski55]

Does this indicate a computer memory problem?

I read a csv file with student names and number in to a dictionary: numsnames

The dictionary has 162 items. key is student number, value is name.

I want to make a QR code for each student from the dictionary:

for key in numsnames.keys():
    filename = f'/home/pedro/winter2020/20BE/QRcodes_20BE/{key}QR.png'
    data = key + ':' + numsnames[key]
    # instantiate QRCode object
    qr = qrcode.QRCode(version=1, box_size=10, border=4)
    # add data to the QR code
    qr.add_data(data)
    # compile the data into a QR code array
    qr.make()
    # transfer the array into an actual image
    img = qr.make_image(fill_color="black", back_color="white")
    # save it to a file
    img.save(filename)

To check, I print the data from the QR code:

QRfiles = os.listdir(savepathQRcodes)
QRfiles.sort()
for f in QRfiles:
    img = cv2.imread(savepathQRcodes + file)
    detector = cv2.QRCodeDetector()
    data, bbox, straight_qrcode = detector.detectAndDecode(img)
    #text = data.split(':')
    #print('number, name: ', text[0], text[1])
    print(data)

What I get has bits missing:

pedro@pedro-512ssd:~/myPython$ ./qrCodes_for_studentsV1.py
numsnames is 162 long.

1825010141:陆遥
2025010101:白雪妮
2025010102:曹颖
2025010103:陈妍朵
2025010104:戴金珂
2025010105:段赵元
2025010106:段卓含

2025010108:范玉虹
2025010109:高萌婧
2025010110:高飒飒
2025010111:郭其平
2025010112:侯文美
2025010113:胡蝶

2025010115:胡沁恬

In all there are 20 names/numbers missing, or 20 QR codes without data.

Is this a computer memory problem??