Convert basestring to str

Signed-off-by: Łukasz Żarnowiecki <dolohow@outlook.com>
Signed-off-by: Nicolas Sebrecht <nicolas.s-dev@laposte.net>

offlineimap/folder/Base.py

@@ -1086,7 +1086,7 @@ class BaseFolder(object):
         MailDirFolder('foo') == MaildirFolder('foo') --> False
         """
 
-        if isinstance(other, basestring):
+        if isinstance(other, str):
             return other == self.name
         return id(self) == id(other)
 

offlineimap/imaputil.py

@@ -101,7 +101,7 @@ def imapsplit(imapstring):
 
     ['(\\HasNoChildren)', '"."', '"INBOX.Sent"']"""
 
-    if not isinstance(imapstring, basestring):
+    if not isinstance(imapstring, str):
         __debug("imapsplit() got a non-string input; working around.")
         # Sometimes, imaplib will throw us a tuple if the input
         # contains a literal.  See Python bug

offlineimap/repository/IMAP.py

@@ -393,7 +393,7 @@ class IMAPRepository(BaseRepository):
             self.imapserver.releaseconnection(imapobj)
         for s in listresult:
             if s == None or \
-                   (isinstance(s, basestring) and s == ''):
+                   (isinstance(s, str) and s == ''):
                 # Bug in imaplib: empty strings in results from
                 # literals. TODO: still relevant?
                 continue