python: more error handling fixes

This is a follow up commit to 221c7e0b38177f5f1dbf0561580c15e8aaa49004
fixing more NULL pointer checks.

Signed-off-by: Justus Winter <4winter@informatik.uni-hamburg.de>

6 files changed, 37 insertions, 37 deletions

diff --git a/bindings/python/notmuch/database.py b/bindings/python/notmuch/database.py
index 0958ce0a..6edb18b6 100644
--- a/bindings/python/notmuch/database.py
+++ b/bindings/python/notmuch/database.py
@@ -159,7 +159,7 @@ class Database(object):
 
     def _assert_db_is_initialized(self):
         """Raises :exc:`NotInitializedError` if self._db is `None`"""
-        if self._db is None:
+        if not self._db:
             raise NotInitializedError()
 
     def create(self, path):
diff --git a/bindings/python/notmuch/filename.py b/bindings/python/notmuch/filename.py
index 469b6a5a..322e6bf1 100644
--- a/bindings/python/notmuch/filename.py
+++ b/bindings/python/notmuch/filename.py
@@ -89,7 +89,7 @@ class Filenames(Python3StringMixIn):
 
         This is the main function that will usually be used by the
         user."""
-        if self._files is None:
+        if not self._files:
             raise NotmuchError(STATUS.NOT_INITIALIZED)
 
         while self._valid(self._files):
diff --git a/bindings/python/notmuch/message.py b/bindings/python/notmuch/message.py
index 883ed233..28723c10 100644
--- a/bindings/python/notmuch/message.py
+++ b/bindings/python/notmuch/message.py
@@ -135,7 +135,7 @@ class Messages(object):
             :meth:`collect_tags` will iterate over the messages and therefore
             will not allow further iterations.
         """
-        if self._msgs is None:
+        if not self._msgs:
             raise NotmuchError(STATUS.NOT_INITIALIZED)
 
         # collect all tags (returns NULL on error)
@@ -160,7 +160,7 @@ class Messages(object):
     _move_to_next.restype = None
 
     def __next__(self):
-        if self._msgs is None:
+        if not self._msgs:
             raise NotmuchError(STATUS.NOT_INITIALIZED)
 
         if not self._valid(self._msgs):
@@ -362,7 +362,7 @@ class Message(Python3StringMixIn):
         :exception: :exc:`NotmuchError` STATUS.NOT_INITIALIZED if the message
                     is not initialized.
         """
-        if self._msg is None:
+        if not self._msg:
             raise NotmuchError(STATUS.NOT_INITIALIZED)
         return Message._get_message_id(self._msg).decode('utf-8', 'ignore')
 
@@ -379,7 +379,7 @@ class Message(Python3StringMixIn):
         :exception: :exc:`NotmuchError` STATUS.NOT_INITIALIZED if the message
                     is not initialized.
         """
-        if self._msg is None:
+        if not self._msg:
             raise NotmuchError(STATUS.NOT_INITIALIZED)
 
         return Message._get_thread_id(self._msg).decode('utf-8', 'ignore')
@@ -402,7 +402,7 @@ class Message(Python3StringMixIn):
         :exception: :exc:`NotmuchError` STATUS.NOT_INITIALIZED if the message
                     is not initialized.
         """
-        if self._msg is None:
+        if not self._msg:
             raise NotmuchError(STATUS.NOT_INITIALIZED)
 
         msgs_p = Message._get_replies(self._msg)
@@ -424,7 +424,7 @@ class Message(Python3StringMixIn):
         :exception: :exc:`NotmuchError` STATUS.NOT_INITIALIZED if the message
                     is not initialized.
         """
-        if self._msg is None:
+        if not self._msg:
             raise NotmuchError(STATUS.NOT_INITIALIZED)
         return Message._get_date(self._msg)
 
@@ -447,7 +447,7 @@ class Message(Python3StringMixIn):
                       is not initialized.
                     * STATUS.NULL_POINTER if any error occured.
         """
-        if self._msg is None:
+        if not self._msg:
             raise NotmuchError(STATUS.NOT_INITIALIZED)
 
         #Returns NULL if any error occurs.
@@ -463,7 +463,7 @@ class Message(Python3StringMixIn):
         :exception: :exc:`NotmuchError` STATUS.NOT_INITIALIZED if the message
               is not initialized.
         """
-        if self._msg is None:
+        if not self._msg:
             raise NotmuchError(STATUS.NOT_INITIALIZED)
         return Message._get_filename(self._msg).decode('utf-8', 'ignore')
 
@@ -473,7 +473,7 @@ class Message(Python3StringMixIn):
         Returns a Filenames() generator with all absolute filepaths for
         messages recorded to have the same Message-ID. These files must
         not necessarily have identical content."""
-        if self._msg is None:
+        if not self._msg:
             raise NotmuchError(STATUS.NOT_INITIALIZED)
 
         files_p = Message._get_filenames(self._msg)
@@ -493,7 +493,7 @@ class Message(Python3StringMixIn):
         :exception: :exc:`NotmuchError` STATUS.NOT_INITIALIZED if the message
               is not initialized.
         """
-        if self._msg is None:
+        if not self._msg:
             raise NotmuchError(STATUS.NOT_INITIALIZED)
         return Message._get_flag(self._msg, flag)
 
@@ -508,7 +508,7 @@ class Message(Python3StringMixIn):
         :exception: :exc:`NotmuchError` STATUS.NOT_INITIALIZED if the message
               is not initialized.
         """
-        if self._msg is None:
+        if not self._msg:
             raise NotmuchError(STATUS.NOT_INITIALIZED)
         self._set_flag(self._msg, flag, value)
 
@@ -522,7 +522,7 @@ class Message(Python3StringMixIn):
                         is not initialized.
                       * STATUS.NULL_POINTER, on error
         """
-        if self._msg is None:
+        if not self._msg:
             raise NotmuchError(STATUS.NOT_INITIALIZED)
 
         tags_p = Message._get_tags(self._msg)
@@ -565,7 +565,7 @@ class Message(Python3StringMixIn):
                   STATUS.NOT_INITIALIZED
                      The message has not been initialized.
        """
-        if self._msg is None:
+        if not self._msg:
             raise NotmuchError(STATUS.NOT_INITIALIZED)
 
         status = self._add_tag(self._msg, _str(tag))
@@ -613,7 +613,7 @@ class Message(Python3StringMixIn):
                    STATUS.NOT_INITIALIZED
                      The message has not been initialized.
         """
-        if self._msg is None:
+        if not self._msg:
             raise NotmuchError(STATUS.NOT_INITIALIZED)
 
         status = self._remove_tag(self._msg, _str(tag))
@@ -654,7 +654,7 @@ class Message(Python3StringMixIn):
                    STATUS.NOT_INITIALIZED
                      The message has not been initialized.
         """
-        if self._msg is None:
+        if not self._msg:
             raise NotmuchError(STATUS.NOT_INITIALIZED)
 
         status = self._remove_all_tags(self._msg)
@@ -712,7 +712,7 @@ class Message(Python3StringMixIn):
                    STATUS.NOT_INITIALIZED
                      The message has not been initialized.
         """
-        if self._msg is None:
+        if not self._msg:
             raise NotmuchError(STATUS.NOT_INITIALIZED)
 
         status = self._freeze(self._msg)
@@ -751,7 +751,7 @@ class Message(Python3StringMixIn):
                    STATUS.NOT_INITIALIZED
                      The message has not been initialized.
         """
-        if self._msg is None:
+        if not self._msg:
             raise NotmuchError(STATUS.NOT_INITIALIZED)
 
         status = self._thaw(self._msg)
@@ -787,7 +787,7 @@ class Message(Python3StringMixIn):
 
         :returns: a :class:`STATUS` value. In short, you want to see
             notmuch.STATUS.SUCCESS here. See there for details."""
-        if self._msg is None:
+        if not self._msg:
             raise NotmuchError(STATUS.NOT_INITIALIZED)
         return Message._tags_to_maildir_flags(self._msg)
 
@@ -814,7 +814,7 @@ class Message(Python3StringMixIn):
 
         :returns: a :class:`STATUS`. In short, you want to see
             notmuch.STATUS.SUCCESS here. See there for details."""
-        if self._msg is None:
+        if not self._msg:
             raise NotmuchError(STATUS.NOT_INITIALIZED)
         return Message._tags_to_maildir_flags(self._msg)
 
@@ -957,7 +957,7 @@ class Message(Python3StringMixIn):
     def __hash__(self):
         """Implement hash(), so we can use Message() sets"""
         file = self.get_filename()
-        if file is None:
+        if not file:
             return None
         return hash(file)
 
diff --git a/bindings/python/notmuch/query.py b/bindings/python/notmuch/query.py
index 0c08aa9e..6132ca00 100644
--- a/bindings/python/notmuch/query.py
+++ b/bindings/python/notmuch/query.py
@@ -70,7 +70,7 @@ class Query(object):
 
     def _assert_query_is_initialized(self):
         """Raises :exc:`NotInitializedError` if self._query is `None`"""
-        if self._query is None:
+        if not self._query:
             raise NotInitializedError()
 
     """notmuch_query_create"""
diff --git a/bindings/python/notmuch/tag.py b/bindings/python/notmuch/tag.py
index d2dc498c..d0f7bb40 100644
--- a/bindings/python/notmuch/tag.py
+++ b/bindings/python/notmuch/tag.py
@@ -90,7 +90,7 @@ class Tags(Python3StringMixIn):
     _move_to_next.restype = None
 
     def __next__(self):
-        if self._tags is None:
+        if not self._tags:
             raise NotmuchError(STATUS.NOT_INITIALIZED)
         if not self._valid(self._tags):
             self._tags = None
diff --git a/bindings/python/notmuch/thread.py b/bindings/python/notmuch/thread.py
index 104710c4..c2347fe7 100644
--- a/bindings/python/notmuch/thread.py
+++ b/bindings/python/notmuch/thread.py
@@ -117,7 +117,7 @@ class Threads(Python3StringMixIn):
     _move_to_next.restype = None
 
     def __next__(self):
-        if self._threads is None:
+        if not self._threads:
             raise NotmuchError(STATUS.NOT_INITIALIZED)
 
         if not self._valid(self._threads):
@@ -141,7 +141,7 @@ class Threads(Python3StringMixIn):
                      # next line raises NotmuchError(STATUS.NOT_INITIALIZED)!!!
                      for thread in threads: print thread
         """
-        if self._threads is None:
+        if not self._threads:
             raise NotmuchError(STATUS.NOT_INITIALIZED)
 
         i = 0
@@ -244,7 +244,7 @@ class Thread(object):
         :exception: :exc:`NotmuchError` STATUS.NOT_INITIALIZED if the thread
                     is not initialized.
         """
-        if self._thread is None:
+        if not self._thread:
             raise NotmuchError(STATUS.NOT_INITIALIZED)
         return Thread._get_thread_id(self._thread).decode('utf-8', 'ignore')
 
@@ -261,7 +261,7 @@ class Thread(object):
         :exception: :exc:`NotmuchError` STATUS.NOT_INITIALIZED if the thread
                     is not initialized.
         """
-        if self._thread is None:
+        if not self._thread:
             raise NotmuchError(STATUS.NOT_INITIALIZED)
         return self._get_total_messages(self._thread)
 
@@ -284,7 +284,7 @@ class Thread(object):
                       * STATUS.NOT_INITIALIZED if query is not inited
                       * STATUS.NULL_POINTER if search_messages failed
         """
-        if self._thread is None:
+        if not self._thread:
             raise NotmuchError(STATUS.NOT_INITIALIZED)
 
         msgs_p = Thread._get_toplevel_messages(self._thread)
@@ -307,7 +307,7 @@ class Thread(object):
         :exception: :exc:`NotmuchError` STATUS.NOT_INITIALIZED if the thread
                     is not initialized.
         """
-        if self._thread is None:
+        if not self._thread:
             raise NotmuchError(STATUS.NOT_INITIALIZED)
         return self._get_matched_messages(self._thread)
 
@@ -321,10 +321,10 @@ class Thread(object):
         The returned string belongs to 'thread' and will only be valid for
         as long as this Thread() is not deleted.
         """
-        if self._thread is None:
+        if not self._thread:
             raise NotmuchError(STATUS.NOT_INITIALIZED)
         authors = Thread._get_authors(self._thread)
-        if authors is None:
+        if not authors:
             return None
         return authors.decode('UTF-8', 'ignore')
 
@@ -334,10 +334,10 @@ class Thread(object):
         The returned string belongs to 'thread' and will only be valid for
         as long as this Thread() is not deleted.
         """
-        if self._thread is None:
+        if not self._thread:
             raise NotmuchError(STATUS.NOT_INITIALIZED)
         subject = Thread._get_subject(self._thread)
-        if subject is None:
+        if not subject:
             return None
         return subject.decode('UTF-8', 'ignore')
 
@@ -349,7 +349,7 @@ class Thread(object):
         :exception: :exc:`NotmuchError` STATUS.NOT_INITIALIZED if the message
                     is not initialized.
         """
-        if self._thread is None:
+        if not self._thread:
             raise NotmuchError(STATUS.NOT_INITIALIZED)
         return Thread._get_newest_date(self._thread)
 
@@ -361,7 +361,7 @@ class Thread(object):
         :exception: :exc:`NotmuchError` STATUS.NOT_INITIALIZED if the message
                     is not initialized.
         """
-        if self._thread is None:
+        if not self._thread:
             raise NotmuchError(STATUS.NOT_INITIALIZED)
         return Thread._get_oldest_date(self._thread)
 
@@ -384,7 +384,7 @@ class Thread(object):
                         is not initialized.
                       * STATUS.NULL_POINTER, on error
         """
-        if self._thread is None:
+        if not self._thread:
             raise NotmuchError(STATUS.NOT_INITIALIZED)
 
         tags_p = Thread._get_tags(self._thread)