如何使用Python为自动发送的账单提醒邮件添加付款单附件？

Hey there! Let's get that payment slip attachment working properly. The root of your problem is that askopenfilename() only returns a file path string, and you're attaching it as plain text with MIMEText—that's why recipients only see the filename instead of the actual file. To send a proper attachment, we need to read the file's binary content and wrap it in the correct MIME object.

Step 1: Add Required Imports #

First, add these modules to handle file attachments:

from email.mime.base import MIMEBase
from email import encoders
import os

Step 2: Fix the Attachment Logic #

Replace your current attachment line (msg.attach(MIMEText(askopenfilename()))) with this code, which reads the file content and attaches it properly:

# Let user select the payment file
file_path = askopenfilename()
if file_path:  # Ensure a file was selected
    # Extract just the filename (without full path) for the email header
    filename = os.path.basename(file_path)
    
    # Open the file in binary mode to read its content
    with open(file_path, "rb") as attachment:
        # Create a base MIME object for binary files
        part = MIMEBase("application", "octet-stream")
        part.set_payload(attachment.read())
    
    # Encode the file content to Base64 (required for email transmission)
    encoders.encode_base64(part)
    
    # Set headers to mark this as an attachment
    part.add_header(
        "Content-Disposition",
        f"attachment; filename= {filename}",
    )
    
    # Attach the file to your email message
    msg.attach(part)

Bonus: Fix the Month Variable Bug #

I noticed another small issue: your month variable only holds the last value from the spreadsheet loop, so all emails will show the same month. To fix this, update how you store data in unpaidMembers:

# Inside the payment check loop
unpaidMembers[client] = (email, month)  # Store email and month as a tuple

Then adjust the email sending loop to use this tuple:

for client, (email, month) in unpaidMembers.items():
    body = f"Client: {client} | Month: {month}"
    print(f'Sending email to {email}...')
    # Rest of your email setup code follows

Full Modified Code #

Here's the complete script with all fixes applied:

import openpyxl, smtplib, sys, os
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
from email.mime.base import MIMEBase
from email import encoders
from tkinter import messagebox
from tkinter.filedialog import askopenfilename

# Opens the spreadsheet and obtains the status of the last payment.
wb = openpyxl.load_workbook('C:/temp/cobranca.xlsx')
sheet = wb['Sheet1']
lastCol = sheet.max_column

# Checks the payment status of each customer.
unpaidMembers = {}
for r in range(2, sheet.max_row + 1):
    for c in range(3, lastCol + 1):
        payment = sheet.cell(row=r, column=c).value
        if payment != 'ok':
            client = sheet.cell(row=r, column=1).value
            email = sheet.cell(row=r, column=2).value
            month = sheet.cell(row=1, column=c).value
            unpaidMembers[client] = (email, month)  # Store email + month
            print(f'Row: {r} | Column: {c} | Client: {client} | Email: {email} | Month: {month}')

# Log in to your email account and send emails
for client, (email, month) in unpaidMembers.items():
    body = f"Client: {client} | Month: {month}"
    print(f'Sending email to {email}...')

    # Create message object instance
    msg = MIMEMultipart()

    # Setup message parameters
    password = "password"
    msg['From'] = "email@email.com"
    msg['To'] = email
    msg['Subject'] = f"{client} - Open honorary."

    # Add message body
    msg.attach(MIMEText(body, 'plain'))

    # Handle attachment
    file_path = askopenfilename()
    if file_path:
        filename = os.path.basename(file_path)
        with open(file_path, "rb") as attachment:
            part = MIMEBase("application", "octet-stream")
            part.set_payload(attachment.read())
        
        encoders.encode_base64(part)
        part.add_header(
            "Content-Disposition",
            f"attachment; filename= {filename}",
        )
        msg.attach(part)

    # Create server and send email
    try:
        server = smtplib.SMTP('mail.omnia.net.br', 587)
        server.starttls()
        server.login(msg['From'], password)
        server.sendmail(msg['From'], email, msg.as_string())
        server.quit()
        print(f"Successfully sent email to {email}")
    except Exception as e:
        print(f"Failed to send email to {email}: {str(e)}")

messagebox.showinfo("System Message", "Reminders sent successfully.")

A couple extra notes:

• I added a try/except block around the server code to catch any sending errors (like wrong password or SMTP issues)
• The MIME type application/octet-stream works for most file types; if you're sending a specific file (like PDF), you can use application/pdf instead for better client support

内容的提问来源于stack exchange，提问作者Guvv