How to Add a text in Email Body with a attachment

Question

Here I have made this code to send mails with an attachment. I need to write "Dear All, Please find attached mail" on email body and add attachement.

# Define the HTML document
mail_content = '''Dear All,
Please find below attachement
'''

# Define a function to attach files as MIMEApplication to the email
##############################################################
def attach_file_to_email(email_message, filename):
    # Open the attachment file for reading in binary mode, and make it a MIMEApplication class
    with open(filename, "rb") as f:
        file_attachment = MIMEApplication(f.read())
    # Add header/name to the attachments    
    file_attachment.add_header(
        "Content-Disposition",
        f"attachment; filename= {filename}",
    )
    # Attach the file to the message
    email_message.attach(file_attachment)
##############################################################    

# Set up the email addresses and password. Please replace below with your email address and password
email_from = '[email protected]'
email_to = '[email protected]'



# Generate today's date to be included in the email Subject
date_str = pd.Timestamp.today().strftime('%Y-%m-%d')

# Create a MIMEMultipart class, and set up the From, To, Subject fields
email_message = MIMEMultipart()

email_message['From'] = email_from 
email_message['To'] = email_to
email_message['Cc'] = Cc



email_message['Subject'] = f'Report email - {date_str}'

# Attach the html doc defined earlier, as a MIMEText html content type to the MIME message
email_message.attach(MIMEText(html, "html"))

# Attach more (documents)
##############################################################
attach_file_to_email(email_message, '/data/Stat20220419.csv')

##############################################################
# Convert it as a string
email_string = email_message.as_string()


    
try:
   smtpObj = smtplib.SMTP('mail.protection.outlook.com',25)
   smtpObj.sendmail(email_from, ['[email protected]], email_string)         
   print ("Successfully sent email")
except smtplib.SMTPException:
    pass
except smtplib.socket.error:
    pass    

Can someone show me how to add to the mail_content to mail body. I have used email_message.attach but it is attaching anothe text file with the text. But I need to show just text in the body.Can someone help?