Python：UnicodeEncodeError：'ascii' 编解码器无法在位置 0 中对字符 '\Ο' 进行编码：序号不在范围内 (128)

Question

I am trying to create a Python script that connects to a database I have created for attendance. Specifically what the script does is connect to the SQLite 3 database that I have created, ask for the school's email and password, and then ask the student for his ID (when my MFRC522 reader/writer arrives this will be just a read command to the board). This is running on a Raspberry Pi 4 Model B 4GB with Raspbian Full. My code:

# coding=utf-8
import smtplib #email library
import sqlite3 #SQLite 3 inteface library
import ssl #encryption library
import string

conn = sqlite3.connect ('students') #connect to the database
email = input("Γράψε το email του σχολείου") #ask for email
password = input("Γράψε τον κωδικό για το email του σχολείου: ") #ask for the email password

def sendemail(): #create the sendemail() function
    port = 465  # For SSL
    smtp_server = "smtp.gmail.com"
    message = "Ο μαθητής έφτασε"


    # Create a secure SSL context
    context = ssl.create_default_context()

    with smtplib.SMTP_SSL(smtp_server, port, context=context) as server:
       server.login(email, password)
       server.sendmail(email, remail, message) #remail is the receiver email

c = conn.cursor() #c is a cursor in the database

mathID = input("Γράψε το ID σου: ") #ask for the student's ID
c.execute('SELECT Mail from parousiologio WHERE ID=?', [mathID]) #we tell the c cursor to execute the SQL command to find the email from the matching ID column
remail= c.fetchall() #we select the data from c.execute()
c.execute('Select Onoma from parousiologio where ID=?', [mathID]) #we do the same thing as the student email but now for the student's name.
mathitis = c.fetchall()
conn.close() #disconnect from the database
sendemail() #run the sendemail() function

Sorry for the fact that the strings are in Greek. I am Greek and this is a project that I am making. I had to translate the comments too before posting.

Anyway, when I execute this code with:

python3 bash\ dedomenon2.py

I get the error in the title. I also tried using PYTHONIOENCODING=utf-8 but still nothing. How can I fix this? Thanks a lot and have a great day!

Answer 1

I assume that the error is on the server.sendmail(email, remail, message) line.

The documentation for sendmail is explicit (emphazise mine):

... msg may be a string containing characters in the ASCII range , or a byte string. A string is encoded to bytes using the ascii codec , and lone \\r and \\n characters are converted to \\r\\n characters. A byte string is not modified.

As you pass a message containing Greek (non ascii) characters, its encoding with the ASCII codec raises the error.

How to fix:

The simplest way is IMHO to use the send_message method:

from email.message import EmailMessage
...
    msg = EmailMessage()
    msg.set_content(message)
    with smtplib.SMTP_SSL(smtp_server, port, context=context) as server:
       server.login(email, password)
       server.send_message(msg, email, remail) #remail is the receiver email

It will automatically encode the message in utf8 and add the relevant headers.