How to close the file after sending emails with an attachment?

Question

I have a loop which sends email with an attachment to the people in emailing list. The problem is, when it comes to the last person in the list, the file I am attaching on email still stays as in use in Windows.

for index, row in f.iterrows():
    print (row["ManagerEmail"]+row["filename"])
    msg = MIMEMultipart()
    msg['From'] = fromaddr
    msg['Subject'] = row["filename"] + f" Sales Letter"
    msg.attach(MIMEText(body, 'plain'))
    filename = row["filename"]
    toaddr = row["ManagerEmail"]
    attachment = open(row["filepath"], "rb")
    part = MIMEBase('application', 'octet-stream')
    part.set_payload((attachment).read())
    encoders.encode_base64(part)
    part.add_header('Content-Disposition', "attachment; filename= %s" % filename)
    msg.attach(part)
    text = msg.as_string()
    server.sendmail(fromaddr, toaddr, text)

Somehow I need to put a parameter at the end to close the file but I do not know how to do that.

Does this answer your question? [Does reading an entire file leave the file handle open?](https://stackoverflow.com/questions/7409780/does-reading-an-entire-file-leave-the-file-handle-open) — mkrieger1, May 05 '22 at 11:57

score 5 · Accepted Answer · answered May 05 '22 at 11:52

Just like you open a file with open() you need to close it with close() As in attachment.close(). Or, even better, use context manager:

with open(row["filepath"], "rb") as attachment:
   # Code that uses attachment file goes here
# Code that no longer uses that file goes here

Context managers guarantee that file will be closed outside of the with block.

How to close the file after sending emails with an attachment?

1 Answers1