bpo-34246: Use no mutable default args in smtplib (GH-8554)

Some methods of the SMTP class use mutable default arguments. Specially
`send_message` is affected as it mutates one of the args by appending items
to it, which has side effects on further calls.

1 files changed, 2 insertions, 2 deletions

diff --git a/Doc/library/smtplib.rst b/Doc/library/smtplib.rst
index e5effd0..8052172 100644
--- a/Doc/library/smtplib.rst
+++ b/Doc/library/smtplib.rst
@@ -419,7 +419,7 @@ An :class:`SMTP` instance has the following methods:
       :exc:`SMTPException`.
 
 
-.. method:: SMTP.sendmail(from_addr, to_addrs, msg, mail_options=[], rcpt_options=[])
+.. method:: SMTP.sendmail(from_addr, to_addrs, msg, mail_options=(), rcpt_options=())
 
    Send mail.  The required arguments are an :rfc:`822` from-address string, a list
    of :rfc:`822` to-address strings (a bare string will be treated as a list with 1
@@ -491,7 +491,7 @@ An :class:`SMTP` instance has the following methods:
 
 
 .. method:: SMTP.send_message(msg, from_addr=None, to_addrs=None, \
-                              mail_options=[], rcpt_options=[])
+                              mail_options=(), rcpt_options=())
 
    This is a convenience method for calling :meth:`sendmail` with the message
    represented by an :class:`email.message.Message` object.  The arguments have