diff --git a/src/calibre/ebooks/oeb/iterator/book.py b/src/calibre/ebooks/oeb/iterator/book.py
index 9dce2c9561..cede2cfc19 100644
--- a/src/calibre/ebooks/oeb/iterator/book.py
+++ b/src/calibre/ebooks/oeb/iterator/book.py
@@ -67,8 +67,7 @@ def extract_book(pathtoebook, tdir, log=None, view_kepub=False, processed=False,
         if not only_input_plugin:
             # Run the HTML preprocess/parsing from the conversion pipeline as
             # well
-            if (processed or (plumber.input_fmt.lower() in {'pdb', 'pdf', 'rb'} and
-                    not hasattr(pathtoopf, 'manifest'))):
+            if processed or (plumber.input_fmt.lower() in {'pdb', 'pdf', 'rb'} and not hasattr(pathtoopf, 'manifest')):
                 if hasattr(pathtoopf, 'manifest'):
                     pathtoopf = write_oebbook(pathtoopf, tdir)
                 pathtoopf = create_oebbook(log, pathtoopf, plumber.opts)
diff --git a/src/calibre/ebooks/oeb/transforms/page_margin.py b/src/calibre/ebooks/oeb/transforms/page_margin.py
index 46906a5847..804be2ce60 100644
--- a/src/calibre/ebooks/oeb/transforms/page_margin.py
+++ b/src/calibre/ebooks/oeb/transforms/page_margin.py
@@ -88,8 +88,7 @@ class RemoveFakeMargins:
                 except:
                     pass
                 else:
-                    if ((hasattr(ti, 'startswith') and ti.startswith('-')) or
-                            (isinstance(ti, numbers.Number) and ti < 0)):
+                    if ((hasattr(ti, 'startswith') and ti.startswith('-')) or (isinstance(ti, numbers.Number) and ti < 0)):
                         raise NegativeTextIndent()
                 return style.marginLeft, style.marginRight, style
         return '', '', None
diff --git a/src/calibre/gui2/tag_browser/model.py b/src/calibre/gui2/tag_browser/model.py
index 46abeb70a9..579a94bca1 100644
--- a/src/calibre/gui2/tag_browser/model.py
+++ b/src/calibre/gui2/tag_browser/model.py
@@ -1233,12 +1233,13 @@ class TagsModel(QAbstractItemModel):  # {{{
                 fm_dest = self.db.metadata_for_field(node.category_key)
                 if fm_dest['kind'] == 'user':
                     fm_src = self.db.metadata_for_field(md.column_name)
-                    if md.column_name in ['authors', 'publisher', 'series'] or \
-                            ((fm_src['is_custom'] and (
-                             fm_src['datatype'] in ['series', 'text', 'enumeration'] and
-                              not fm_src['is_multiple']))or
-                             (fm_src['datatype'] == 'composite' and
-                              fm_src['display'].get('make_category', False))):
+                    if md.column_name in ['authors', 'publisher', 'series'] or (
+                               (fm_src['is_custom'] and (
+                                fm_src['datatype'] in ['series', 'text', 'enumeration'] and
+                                not fm_src['is_multiple'])) or
+                               (fm_src['datatype'] == 'composite' and
+                                fm_src['display'].get('make_category', False))
+                            ):
                         mime = 'application/calibre+from_library'
                         ids = list(map(int, md.data(mime).data().split()))
                         self.handle_user_category_drop(node, ids, md.column_name)