From: Benjamin Drung <benjamin.drung@canonical.com>
Date: Tue, 13 Dec 2022 15:06:02 +0100
Subject: Python 3 support

Do not run 2to3 in `setup.py`. Instead run it once:

```
2to3 -w mailer.py
```

Signed-off-by: Benjamin Drung <benjamin.drung@canonical.com>
---
 mailer.py | 37 ++++++++++++++++++-------------------
 setup.py  |  5 -----
 2 files changed, 18 insertions(+), 24 deletions(-)

diff --git a/mailer.py b/mailer.py
index 1aa8e94..f391503 100644
--- a/mailer.py
+++ b/mailer.py
@@ -29,11 +29,10 @@ Sample code:
     sender.send(message)
 
 """
-from __future__ import with_statement
 import smtplib
 import socket
 import threading
-import Queue
+import queue
 import uuid
 
 # this is to support name changes
@@ -131,28 +130,28 @@ class Mailer(object):
         we created in send()
         """
         me = msg.From
-        if isinstance(msg.To, basestring):
+        if isinstance(msg.To, str):
             to = [msg.To]
         else:
             to = list(msg.To)
 
         cc = []
         if msg.CC:
-            if isinstance(msg.CC, basestring):
+            if isinstance(msg.CC, str):
                 cc = [msg.CC]
             else:
                 cc = list(msg.CC)
 
         bcc = []
         if msg.BCC:
-            if isinstance(msg.BCC, basestring):
+            if isinstance(msg.BCC, str):
                 bcc = [msg.BCC]
             else:
                 bcc = list(msg.BCC)
 
         rto = []
         if msg.RTo:
-            if isinstance(msg.RTo, basestring):
+            if isinstance(msg.RTo, str):
                 rto = [msg.RTo]
             else:
                 rto = list(msg.RTo)
@@ -197,7 +196,7 @@ class Message(object):
         attachments = params.get('attachments', None)
         if attachments:
             for attachment in attachments:
-                if isinstance(attachment, basestring):
+                if isinstance(attachment, str):
                     self.attachments.append((attachment, None, None, None, None))
                 else:
                     try:
@@ -216,14 +215,14 @@ class Message(object):
         self.CC         = params.get('cc', None)
         self.BCC        = params.get('bcc', None)
         self.From       = params.get('from', None) # string or iterable
-        self.Subject    = params.get('subject', u'') # string
+        self.Subject    = params.get('subject', '') # string
         self.Body       = params.get('body', None)
         self.Html       = params.get('html', None)
         self.Date       = params.get('date', time.strftime("%a, %d %b %Y %H:%M:%S %z", time.gmtime()))
         self.charset    = params.get('charset', 'us-ascii')
         self.Headers    = params.get('headers', {})
 
-        if isinstance(self.Body, unicode):
+        if isinstance(self.Body, str):
             self.Body = self.Body.encode(self.charset)
 
         self.message_id = self.make_key()
@@ -273,34 +272,34 @@ class Message(object):
             msg['From'] = self.From
 
         else:
-            if isinstance(self.Subject, unicode):
+            if isinstance(self.Subject, str):
                 subject = self.Subject
             else:
-                subject = unicode(self.Subject, self.charset)
+                subject = str(self.Subject, self.charset)
             msg['Subject'] = str(make_header([(subject, self.charset)]))
 
-            if isinstance(self.From, unicode):
+            if isinstance(self.From, str):
                 from_ = self.From
             else:
-                from_ = unicode(self.From, self.charset)
+                from_ = str(self.From, self.charset)
             msg['From'] = str(make_header([(from_, self.charset)]))
 
 
-        if isinstance(self.To, basestring):
+        if isinstance(self.To, str):
             msg['To'] = self.To
         else:
             self.To = list(self.To)
             msg['To'] = ", ".join(self.To)
 
         if self.RTo:
-            if isinstance(self.RTo, basestring):
+            if isinstance(self.RTo, str):
                 msg.add_header('reply-to', self.RTo)
             else:
                 self.RTo = list(self.RTo)
                 msg.add_header('reply-to', ", ".join(self.RTo))
 
         if self.CC:
-            if isinstance(self.CC, basestring):
+            if isinstance(self.CC, str):
                 msg['CC'] = self.CC
             else:
                 self.CC = list(self.CC)
@@ -308,7 +307,7 @@ class Message(object):
 
 
         if self.BCC:
-            if isinstance(self.BCC, basestring):
+            if isinstance(self.BCC, str):
                 msg['BCC'] = self.BCC
             else:
                 self.BCC = list(self.BCC)
@@ -316,7 +315,7 @@ class Message(object):
 
 
         if self.Headers:
-            for key, value in self.Headers.items():
+            for key, value in list(self.Headers.items()):
                 msg[key] = str(value).encode(self.charset)
 
 
@@ -420,7 +419,7 @@ class Manager(threading.Thread):
     def __init__(self, mailer=None, callback=None, **kwargs):
         threading.Thread.__init__(self)
 
-        self.queue = Queue.Queue()
+        self.queue = queue.Queue()
         self.mailer = mailer
         self.abort = False
         self.callback = callback
diff --git a/setup.py b/setup.py
index 60030cd..a487083 100644
--- a/setup.py
+++ b/setup.py
@@ -1,10 +1,6 @@
 from setuptools import setup
 import sys
 
-extra = {}
-if sys.version_info >= (3, 0):
-    extra.update(use_2to3=True)
-
 setup(
     name='mailer',
     version="0.8.1",
@@ -24,5 +20,4 @@ setup(
         'Programming Language :: Python',
         'Programming Language :: Python :: 3',
     ],
-    **extra
 )