在Python3中，当我将.csv文件作为附件发送时，它缺少行

import csv
import smtplib
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
from email.mime.base import MIMEBase
from email import encoders

# 读取.csv文件
with open('data.csv', 'r') as file:
    reader = csv.reader(file)
    data = list(reader)

# 构建邮件
msg = MIMEMultipart()
msg['From'] = 'sender@example.com'
msg['To'] = 'receiver@example.com'
msg['Subject'] = 'CSV File'

# 添加邮件正文
body = 'Please find the attached CSV file.'
msg.attach(MIMEText(body, 'plain'))

# 添加附件
attachment = MIMEBase('application', 'octet-stream')
attachment.set_payload(open('data.csv', 'rb').read())
encoders.encode_base64(attachment)
attachment.add_header('Content-Disposition', 'attachment', filename='data.csv')
msg.attach(attachment)

# 发送邮件
smtp = smtplib.SMTP('smtp.example.com', 587)
smtp.starttls()
smtp.login('username', 'password')
smtp.send_message(msg)
smtp.quit()