Decode bytes objects obtained in Python 3

The imaplib module in Python 3 returns payloads as bytes, which are not
automatically converted to strs. That's a good thing! But we need to
encode manually.

mail_check_mailbox_size/models/fetchmail.py

@@ -53,7 +53,7 @@ class Fetchmail(models.Model):
                 number_of_messages_all = 0
                 size_all = 0
                 for item in list:
-                    x = item.split()
+                    x = item.decode().split()
                     mailbox = x[-1]
 
                     # Select the desired folder
@@ -64,13 +64,14 @@ class Fetchmail(models.Model):
                             "Server %s responded %s for folder %s"
                             % (server.name, number_of_messages, mailbox))
                         continue
-                    number_of_messages_all += int(number_of_messages[0])
+                    number_of_messages_all += int(
+                        number_of_messages[0].decode())
 
                     size_folder = 0
                     # Go through all the messages in the selected folder
                     typ, msg = imap_server.search(None, 'ALL')
                     # Find the first and last messages
-                    m = [int(msg_part) for msg_part in msg[0].split()]
+                    m = [int(msg_part.decode()) for msg_part in msg[0].split()]
                     m.sort()
                     if m:
                         message_set = "%d:%d" % (m[0], m[-1])
@@ -78,7 +79,7 @@ class Fetchmail(models.Model):
                             message_set, "(UID RFC822.SIZE)")
                         for i in range(m[-1]):
                             tmp = sizes_response[i].split()
-                            size_folder += int(tmp[-1].replace(')', ''))
+                            size_folder += int(tmp[-1].decode().replace(')', ''))
                     else:
                         size_folder = 0
                     result_msg += (
@@ -87,7 +88,11 @@ class Fetchmail(models.Model):
                         "<td style=\"text-align:right\">%i</td>"
                         "<td style=\"text-align:right\">%s</td>"
                         "</tr>"
-                    ) % (mailbox, int(number_of_messages[0]), size_folder)
+                    ) % (
+                        mailbox,
+                        int(number_of_messages[0].decode()),
+                        size_folder
+                    )
                     size_all += size_folder
 
                 result_msg += _(