write better list/set/dict comprehensions (auto-fix)

ruff 'C4'

manual/custom.py

@@ -198,7 +198,7 @@ details and examples.
         lines += [f'.. _calibredb-{language}-{cmd}:', '']
         lines += [cmd, '~'*20, '']
         usage = parser.usage.strip()
-        usage = [i for i in usage.replace('%prog', 'calibredb').splitlines()]
+        usage = list(usage.replace('%prog', 'calibredb').splitlines())
         cmdline = '    '+usage[0]
         usage = usage[1:]
         usage = [re.sub(rf'({cmd})([^a-zA-Z0-9])', r':command:`\1`\2', i) for i in usage]

recipes/bloomberg-business-week.recipe

@@ -124,7 +124,7 @@ class Bloomberg(BasicNewsRecipe):
             cat = '<div class="cat">' + data['primaryCategory'] + '</div>'
 
         if 'abstract' in data and data['abstract'] and data['abstract'] is not None:
-            subhead = '<div class="subhead"><ul><li>' + '</li><li>'.join([x for x in data['abstract']]) + '</li></ul></div>'
+            subhead = '<div class="subhead"><ul><li>' + '</li><li>'.join(list(data['abstract'])) + '</li></ul></div>'
         elif 'summary' in data and data['summary']:
             subhead = '<div class="subhead"><p>' + data['summary'] + '</p></div>'
 

recipes/bloomberg.recipe

@@ -134,7 +134,7 @@ class Bloomberg(BasicNewsRecipe):
             cat = '<div class="cat">' + data['primaryCategory'] + '</div>'
 
         if 'abstract' in data and data['abstract'] and data['abstract'] is not None:
-            subhead = '<div class="subhead"><ul><li>' + '</li><li>'.join([x for x in data['abstract']]) + '</li></ul></div>'
+            subhead = '<div class="subhead"><ul><li>' + '</li><li>'.join(list(data['abstract'])) + '</li></ul></div>'
         elif 'summary' in data and data['summary']:
             subhead = '<div class="subhead"><p>' + data['summary'] + '</p></div>'
 

recipes/factcheck.recipe

@@ -13,6 +13,6 @@ class FactCheckOrg(BasicNewsRecipe):
     masthead_url = 'http://factcheck.org/wp-content/themes/Streamline/images/headernew.jpg'
     cover_url = 'http://factcheck.org/wp-content/themes/Streamline/images/headernew.jpg'
 
-    remove_tags = [dict({'id': ['footer', 'footerabout', 'sidebar']})]
+    remove_tags = [{'id': ['footer', 'footerabout', 'sidebar']}]
 
     feeds = [(u'Factcheck', u'feed://www.factcheck.org/feed/')]

recipes/gry_online_pl.recipe

@@ -21,7 +21,7 @@ class GryOnlinePl(BasicNewsRecipe):
     keep_only_tags = [dict(name='div', attrs={'class': [
                            'gc660', 'gc660 S013', 'news_endpage_tit', 'news_container', 'news']})]
     remove_tags = [
-        dict({'class': ['nav-social', 'add-info', 'smlb', 'lista lista3 lista-gry', 'S013po', 'S013-npb', 'zm_gfx_cnt_bottom', 'ocen-txt', 'wiecej-txt', 'wiecej-txt2', 'social-for-old-news', 'social-for-old-rec']})]  # noqa: E501
+        {'class': ['nav-social', 'add-info', 'smlb', 'lista lista3 lista-gry', 'S013po', 'S013-npb', 'zm_gfx_cnt_bottom', 'ocen-txt', 'wiecej-txt', 'wiecej-txt2', 'social-for-old-news', 'social-for-old-rec']}]  # noqa: E501
     feeds = [
         (u'Newsy', 'http://www.gry-online.pl/rss/news.xml'),
         ('Teksty', u'http://www.gry-online.pl/rss/teksty.xml')]

recipes/reuters.recipe

@@ -140,7 +140,7 @@ class Reuters(BasicNewsRecipe):
                 for y in x['templates']:
                     if 'author' in y['cid']:
                         body += '<p>'
-                        auths = [x for x in y.get('authors_names', [])]
+                        auths = list(y.get('authors_names', []))
                         if auths:
                             body += (
                                 '<div class="auth">' + 'By ' + ', '.join(auths) + '</div>'

ruff-strict-pep8.toml

@@ -17,8 +17,14 @@ exclude = [
 quote-style = 'single'
 
 [lint]
-ignore = ['E402', 'E722', 'E741', 'UP012', 'UP030', 'UP032', 'UP038']
+ignore = [
-select = ['E', 'F', 'I', 'W', 'INT', 'Q', 'UP', 'YTT', 'TID']
+    'E402', 'E722', 'E741',
+    'UP012', 'UP030', 'UP032', 'UP038', 'C408', 'C413', 'C417', 'C420',
+]
+select = [
+    'E', 'F', 'I', 'W', 'INT',
+    'Q', 'UP', 'YTT', 'TID', 'C4',
+]
 
 [lint.per-file-ignores]
 "recipes/*" = ['UP']

setup/translations.py

@@ -357,7 +357,7 @@ class Translations(POT):  # {{{
         l = {}
         lc_dataf = os.path.join(os.path.dirname(os.path.abspath(__file__)), 'lc_data.py')
         exec(compile(open(lc_dataf, 'rb').read(), lc_dataf, 'exec'), l, l)
-        lcdata = {k:{k1:v1 for k1, v1 in v} for k, v in l['data']}
+        lcdata = {k:dict(v) for k, v in l['data']}
         self.info('Compiling main UI translation files...')
         fmap = {f:self.mo_file(f) for f in self.po_files()}
         files = [(f, fmap[f][1]) for f in self.po_files()]

src/calibre/customize/__init__.py

@@ -573,10 +573,10 @@ class CatalogPlugin(Plugin):  # {{{
             # Validate requested_fields
             if requested_fields - all_fields:
                 from calibre.library import current_library_name
-                invalid_fields = sorted(list(requested_fields - all_fields))
+                invalid_fields = sorted(requested_fields - all_fields)
                 print('invalid --fields specified: %s' % ', '.join(invalid_fields))
                 print("available fields in '%s': %s" %
-                      (current_library_name(), ', '.join(sorted(list(all_fields)))))
+                      (current_library_name(), ', '.join(sorted(all_fields))))
                 raise ValueError('unable to generate catalog with specified fields')
 
             fields = [x for x in of if x in all_fields]

src/calibre/db/cli/cmd_set_metadata.py

@@ -152,7 +152,7 @@ def main(opts, args, dbctx):
             raise SystemExit(_('No book with id: %s in the database') % book_id)
 
     if opts.field:
-        fields = {k: v for k, v in get_fields(dbctx)}
+        fields = dict(get_fields(dbctx))
         fields['title_sort'] = fields['sort']
         vals = {}
         for x in opts.field:

src/calibre/db/fields.py

@@ -366,7 +366,7 @@ class CompositeField(OneToOneField):
         for book_id in candidates:
             vals = self.get_value_with_cache(book_id, get_metadata)
             if splitter:
-                length = len(list(vv.strip() for vv in vals.split(splitter) if vv.strip()))
+                length = len([vv.strip() for vv in vals.split(splitter) if vv.strip()])
             elif vals.strip():
                 length = 1
             else:

src/calibre/db/legacy.py

@@ -799,7 +799,7 @@ class LibraryDatabase:
             with self.new_api.write_lock:
                 self.new_api._set_field(field, {book_id:val for book_id in ids}, allow_case_change=False)
             if extras is not None:
-                self.new_api._set_field(field + '_index', {book_id:val for book_id, val in zip(ids, extras)})
+                self.new_api._set_field(field + '_index', dict(zip(ids, extras)))
         if notify:
             self.notify('metadata', list(ids))
 

src/calibre/db/tables.py

@@ -234,7 +234,7 @@ class ManyToOneTable(Table):
             bcm[book] = item_id
 
     def fix_link_table(self, db):
-        linked_item_ids = {item_id for item_id in itervalues(self.book_col_map)}
+        linked_item_ids = set(itervalues(self.book_col_map))
         extra_item_ids = linked_item_ids - set(self.id_map)
         if extra_item_ids:
             for item_id in extra_item_ids:

src/calibre/db/tests/writing.py

@@ -1019,9 +1019,9 @@ class WritingTest(BaseTest):
         cache.set_field('publisher', {1:'random'})
         cache.set_link_map('publisher', {'random': 'url2'})
         links = cache.get_all_link_maps_for_book(1)
-        self.assertSetEqual({v for v in links.keys()}, {'tags', 'publisher'}, 'Wrong link keys')
+        self.assertSetEqual(set(links.keys()), {'tags', 'publisher'}, 'Wrong link keys')
-        self.assertSetEqual({v for v in links['tags'].keys()}, {'foo', }, 'Should be "foo"')
+        self.assertSetEqual(set(links['tags'].keys()), {'foo', }, 'Should be "foo"')
-        self.assertSetEqual({v for v in links['publisher'].keys()}, {'random', }, 'Should be "random"')
+        self.assertSetEqual(set(links['publisher'].keys()), {'random', }, 'Should be "random"')
         self.assertEqual('url', links['tags']['foo'], 'link for tag foo is wrong')
         self.assertEqual('url2', links['publisher']['random'], 'link for publisher random is wrong')
 

src/calibre/db/write.py

@@ -129,7 +129,7 @@ def clean_identifier(typ, val):
 
 def adapt_identifiers(to_tuple, x):
     if not isinstance(x, dict):
-        x = {k:v for k, v in (y.partition(':')[0::2] for y in to_tuple(x))}
+        x = dict(y.partition(':')[0::2] for y in to_tuple(x))
     ans = {}
     for k, v in iteritems(x):
         k, v = clean_identifier(k, v)

src/calibre/devices/kobo/driver.py

@@ -2260,7 +2260,7 @@ class KOBOTOUCH(KOBO):
         return extra_sheet
 
     def get_extra_css_rules(self, sheet, css_rule):
-        return [r for r in sheet.cssRules.rulesOfType(css_rule)]
+        return list(sheet.cssRules.rulesOfType(css_rule))
 
     def get_extra_css_rules_widow_orphan(self, sheet):
         from css_parser.css import CSSRule

src/calibre/devices/mtp/driver.py

@@ -487,7 +487,7 @@ class MTP_DEVICE(BASE):
         self.report_progress(0, _('Transferring books to device...'))
         i, total = 0, len(files)
 
-        routing = {fmt:dest for fmt,dest in self.get_pref('rules')}
+        routing = dict(self.get_pref('rules'))
 
         for infile, fname, mi in zip(files, names, metadata):
             path = self.create_upload_path(prefix, mi, fname, routing)

src/calibre/ebooks/conversion/plugins/fb2_input.py

@@ -105,7 +105,7 @@ class FB2Input(InputFormatPlugin):
         # Handle links of type note and cite
         notes = {a.get('href')[1:]: a for a in result.xpath('//a[@link_note and @href]') if a.get('href').startswith('#')}
         cites = {a.get('link_cite'): a for a in result.xpath('//a[@link_cite]') if not a.get('href', '')}
-        all_ids = {x for x in result.xpath('//*/@id')}
+        all_ids = set(result.xpath('//*/@id'))
         for cite, a in iteritems(cites):
             note = notes.get(cite, None)
             if note:

src/calibre/ebooks/covers.py

@@ -318,7 +318,7 @@ ColorTheme = namedtuple('ColorTheme', 'color1 color2 contrast_color1 contrast_co
 
 
 def to_theme(x):
-    return {k:v for k, v in zip(ColorTheme._fields[:4], x.split())}
+    return dict(zip(ColorTheme._fields[:4], x.split()))
 
 
 fallback_colors = to_theme('ffffff 000000 000000 ffffff')

src/calibre/ebooks/docx/block_styles.py

@@ -128,7 +128,7 @@ def read_single_border(parent, edge, XPath, get):
                 width = min(96, max(2, float(sz))) / 8
             except (ValueError, TypeError):
                 pass
-    return {p:v for p, v in zip(border_props, (padding, width, style, color))}
+    return dict(zip(border_props, (padding, width, style, color)))
 
 
 def read_border(parent, dest, XPath, get, border_edges=border_edges, name='pBdr'):

src/calibre/ebooks/lrf/lrs/convert_from.py

@@ -108,7 +108,7 @@ class LrsParser:
 
     def process_paragraph(self, tag):
         p = Paragraph()
-        contents = [i for i in tag.contents]
+        contents = list(tag.contents)
         if contents:
             if isinstance(contents[0], NavigableString):
                 contents[0] = contents[0].string.lstrip()

src/calibre/ebooks/metadata/author_mapper.py

@@ -127,7 +127,7 @@ def uniq(vals, kmap=icu_lower):
     lvals = (kmap(x) for x in vals)
     seen = set()
     seen_add = seen.add
-    return list(x for x, k in zip(vals, lvals) if k not in seen and not seen_add(k))
+    return [x for x, k in zip(vals, lvals) if k not in seen and not seen_add(k)]
 
 
 def compile_rules(rules):

src/calibre/ebooks/metadata/odt.py

@@ -63,7 +63,7 @@ def uniq(vals):
     vals = vals or ()
     seen = set()
     seen_add = seen.add
-    return list(x for x in vals if x not in seen and not seen_add(x))
+    return [x for x in vals if x not in seen and not seen_add(x)]
 
 
 def get_metadata(stream, extract_cover=True):

src/calibre/ebooks/metadata/opf3.py

@@ -34,7 +34,7 @@ def uniq(vals):
     vals = vals or ()
     seen = set()
     seen_add = seen.add
-    return list(x for x in vals if x not in seen and not seen_add(x))
+    return [x for x in vals if x not in seen and not seen_add(x)]
 
 
 def dump_dict(cats):

src/calibre/ebooks/metadata/sources/amazon.py

@@ -564,9 +564,9 @@ class Worker(Thread):  # Get details {{{
         res = self.tostring(elem, encoding='unicode', method='text')
         if only_printable:
             try:
-                filtered_characters = list(s for s in res if s.isprintable())
+                filtered_characters = [s for s in res if s.isprintable()]
             except AttributeError:
-                filtered_characters = list(s for s in res if s in string.printable)
+                filtered_characters = [s for s in res if s in string.printable]
             res = ''.join(filtered_characters)
         return res.strip()
 
@@ -1395,8 +1395,8 @@ class Amazon(Source):
                 q['field-keywords'] += ' ' + q.pop(f, '')
             q['field-keywords'] = q['field-keywords'].strip()
 
-        encoded_q = dict([(x.encode('utf-8', 'ignore'), y.encode(
+        encoded_q = {x.encode('utf-8', 'ignore'): y.encode(
-            'utf-8', 'ignore')) for x, y in q.items()])
+            'utf-8', 'ignore') for x, y in q.items()}
         url_query = urlencode(encoded_q)
         # amazon's servers want IRIs with unicode characters not percent esaped
         parts = []

src/calibre/ebooks/metadata/sources/base.py

@@ -180,7 +180,7 @@ class Option:
         self.name, self.type, self.default, self.label, self.desc = (name,
                 type_, default, label, desc)
         if choices and not isinstance(choices, dict):
-            choices = dict([(x, x) for x in choices])
+            choices = {x: x for x in choices}
         self.choices = choices
 
 

src/calibre/ebooks/metadata/tag_mapper.py

@@ -119,7 +119,7 @@ def uniq(vals, kmap=icu_lower):
     lvals = (kmap(x) for x in vals)
     seen = set()
     seen_add = seen.add
-    return list(x for x, k in zip(vals, lvals) if k not in seen and not seen_add(k))
+    return [x for x, k in zip(vals, lvals) if k not in seen and not seen_add(k)]
 
 
 def map_tags(tags, rules=()):

src/calibre/ebooks/mobi/reader/headers.py

@@ -26,7 +26,7 @@ def uniq(vals):
     vals = vals or ()
     seen = set()
     seen_add = seen.add
-    return list(x for x in vals if x not in seen and not seen_add(x))
+    return [x for x in vals if x not in seen and not seen_add(x)]
 
 
 class EXTHHeader:  # {{{

src/calibre/ebooks/oeb/polish/check/opf.py

@@ -214,7 +214,7 @@ class MultipleCovers(BaseError):
         self.all_locations = [(name, lnum, None) for lnum in sorted(locs)]
 
     def __call__(self, container):
-        items = [e for e in container.opf_xpath('/opf:package/opf:metadata/opf:meta[@name="cover"]')]
+        items = list(container.opf_xpath('/opf:package/opf:metadata/opf:meta[@name="cover"]'))
         [container.remove_from_xml(e) for e in items[1:]]
         container.dirty(self.name)
         return True

src/calibre/ebooks/oeb/polish/fonts.py

@@ -112,7 +112,7 @@ def change_font_in_sheet(container, sheet, old_name, new_name, sheet_name):
         elif rule.type == rule.FONT_FACE_RULE:
             ff = rule.style.getProperty('font-family')
             if ff is not None:
-                families = {x for x in parse_font_family(css_text(ff.propertyValue))}
+                families = set(parse_font_family(css_text(ff.propertyValue)))
                 if old_name in families:
                     changed = True
                     removals.append(rule)

src/calibre/ebooks/oeb/polish/utils.py

@@ -117,7 +117,7 @@ def corrected_case_for_name(container, name):
             correctx = x
         else:
             try:
-                candidates = {q for q in os.listdir(os.path.dirname(container.name_to_abspath(base)))}
+                candidates = set(os.listdir(os.path.dirname(container.name_to_abspath(base))))
             except OSError:
                 return None  # one of the non-terminal components of name is a file instead of a directory
             for q in candidates:
@@ -213,7 +213,7 @@ def lead_text(top_elem, num_words=10):
         if attr == 'text':
             if elem is not top_elem:
                 stack.append((elem, 'tail'))
-            stack.extend(reversed(list((c, 'text') for c in elem.iterchildren('*'))))
+            stack.extend(reversed([(c, 'text') for c in elem.iterchildren('*')]))
     return ' '.join(words[:num_words])
 
 

src/calibre/gui2/actions/convert.py

@@ -177,7 +177,7 @@ class ConvertAction(InterfaceActionWithLibraryDrop):
             converted_func, extra_job_args=[], rows_are_ids=False):
         for func, args, desc, fmt, id, temp_files in jobs:
             func, _, parts = func.partition(':')
-            parts = {x for x in parts.split(';')}
+            parts = set(parts.split(';'))
             input_file = args[0]
             input_fmt = os.path.splitext(input_file)[1]
             core_usage = 1

src/calibre/gui2/actions/preferences.py

@@ -46,7 +46,7 @@ class PreferencesAction(InterfaceAction):
     def initialization_complete(self):
         # Add the individual preferences to the menu.
         # First, sort them into the same order as shown in the preferences dialog
-        plugins = sorted([p for p in preferences_plugins()],
+        plugins = sorted(preferences_plugins(),
                          key=lambda p: p.category_order * 100 + p.name_order)
 
         pm = self.preferences_menu

src/calibre/gui2/custom_column_widgets.py

@@ -891,8 +891,8 @@ def get_field_list(db, use_defaults=False, pref_data_override=None):
 
 
 def get_custom_columns_to_display_in_editor(db):
-    return list([k[0] for k in
+    return [k[0] for k in
-        get_field_list(db, use_defaults=db.prefs['edit_metadata_ignore_display_order']) if k[1]])
+        get_field_list(db, use_defaults=db.prefs['edit_metadata_ignore_display_order']) if k[1]]
 
 
 def populate_metadata_page(layout, db, book_id, bulk=False, two_column=False, parent=None):

src/calibre/gui2/dialogs/tag_categories.py

@@ -230,7 +230,7 @@ class TagCategories(QDialog, Ui_TagCategories):
     def fill_applied_items(self):
         ccn = self.current_cat_name
         if ccn:
-            self.applied_items = [v for v in self.user_categories[ccn]]
+            self.applied_items = list(self.user_categories[ccn])
             self.applied_items.sort(key=self.item_sort_key)
         else:
             self.applied_items = []

src/calibre/gui2/dialogs/tag_editor.py

@@ -75,9 +75,9 @@ class TagEditor(QDialog, Ui_TagEditor):
             self.applied_tags.setSelectionMode(QAbstractItemView.SelectionMode.ExtendedSelection)
 
         if key:
-            all_tags = [tag for tag in self.db.all_custom(label=key)]
+            all_tags = list(self.db.all_custom(label=key))
         else:
-            all_tags = [tag for tag in self.db.all_tags()]
+            all_tags = list(self.db.all_tags())
         all_tags = sorted(set(all_tags) - set(tags), key=sort_key)
         self.all_tags_model = QStringListModel(all_tags)
         p = QSortFilterProxyModel()

src/calibre/gui2/dialogs/template_dialog.py

@@ -958,7 +958,7 @@ def evaluate(book, context):
         self.textbox.set_clicked_line_numbers(set())
 
     def set_all_button_pressed(self):
-        self.textbox.set_clicked_line_numbers({i for i in range(1, self.textbox.blockCount()+1)})
+        self.textbox.set_clicked_line_numbers(set(range(1, self.textbox.blockCount()+1)))
 
     def toggle_button_pressed(self):
         ln = self.breakpoint_line_box.value()

src/calibre/gui2/library/delegates.py

@@ -560,7 +560,7 @@ class CcTextDelegate(StyledItemDelegate, UpdateEditorGeometry, EditableTextDeleg
                 editor = EditWithComplete(parent)
             editor.set_separator(None)
             editor.set_clear_button_enabled(False)
-            complete_items = sorted(list(m.db.all_custom(label=key)), key=sort_key)
+            complete_items = sorted(m.db.all_custom(label=key), key=sort_key)
             editor.update_items_cache(complete_items)
         else:
             editor = QLineEdit(parent)

src/calibre/gui2/library/views.py

@@ -1335,7 +1335,7 @@ class BooksView(QTableView):  # {{{
     def visible_columns(self):
         h = self.horizontalHeader()
         logical_indices = (x for x in range(h.count()) if not h.isSectionHidden(x))
-        rmap = {i:x for i, x in enumerate(self.column_map)}
+        rmap = dict(enumerate(self.column_map))
         return (rmap[h.visualIndex(x)] for x in logical_indices if h.visualIndex(x) > -1)
 
     def refresh_book_details(self, force=False):

src/calibre/gui2/preferences/coloring.py

@@ -1281,7 +1281,7 @@ class EditRules(QWidget):  # {{{
 
     def move_rows(self, moving_up=True):
         sm = self.rules_view.selectionModel()
-        rows = sorted(list(sm.selectedRows()), reverse=not moving_up)
+        rows = sorted(sm.selectedRows(), reverse=not moving_up)
         if rows:
             if rows[0].row() == (0 if moving_up else self.model.rowCount() - 1):
                 return

src/calibre/gui2/preferences/look_feel.py

@@ -353,7 +353,7 @@ class TBPartitionedFields(DisplayedFields):  # {{{
             ans = [[k, True] for k in cats.keys()]
             self.changed = True
         elif pref_data_override:
-            po = {k:v for k,v in pref_data_override}
+            po = dict(pref_data_override)
             ans = [[k, po.get(k, True)] for k in cats.keys()]
             self.changed = True
         else:
@@ -389,7 +389,7 @@ class BDVerticalCats(DisplayedFields):  # {{{
             ans = [[k, False] for k in cats]
             self.changed = True
         elif pref_data_override:
-            ph = {k:v for k,v in pref_data_override}
+            ph = dict(pref_data_override)
             ans = [[k, ph.get(k, False)] for k in cats]
             self.changed = True
         else:

src/calibre/gui2/preferences/look_feel_tabs/tb_hierarchy.py

@@ -37,7 +37,7 @@ class TBHierarchicalFields(DisplayedFields):  # {{{
             ans = [[k, False] for k in cats]
             self.changed = True
         elif pref_data_override:
-            ph = {k:v for k,v in pref_data_override}
+            ph = dict(pref_data_override)
             ans = [[k, ph.get(k, False)] for k in cats]
             self.changed = True
         else:

src/calibre/gui2/store/config/chooser/results_view.py

@@ -16,7 +16,7 @@ class ResultsView(QTreeView):
     def __init__(self, parent=None):
         QTreeView.__init__(self,parent)
 
-        self._model = Matches([p for p in store_plugins()])
+        self._model = Matches(list(store_plugins()))
         self.setModel(self._model)
 
         self.setIconSize(QSize(24, 24))

src/calibre/gui2/tag_browser/model.py

@@ -636,7 +636,7 @@ class TagsModel(QAbstractItemModel):  # {{{
                         key, (category_icon_map['user:'] if key.startswith('@') else category_icon_map['custom:'])))
 
             if key.startswith('@'):
-                path_parts = [p for p in key.split('.')]
+                path_parts = list(key.split('.'))
                 path = ''
                 last_category_node = self.root_item
                 tree_root = self.user_category_node_tree
@@ -1547,7 +1547,7 @@ class TagsModel(QAbstractItemModel):  # {{{
                 self.use_position_based_index_on_next_recount = True
                 return True
 
-            for c in sorted(list(user_cats.keys()), key=sort_key):
+            for c in sorted(user_cats.keys(), key=sort_key):
                 if icu_lower(c).startswith(ckey_lower):
                     if len(c) == len(ckey):
                         if strcmp(ckey, nkey) != 0 and \
@@ -1652,13 +1652,13 @@ class TagsModel(QAbstractItemModel):  # {{{
             if ucat.get(new_name, None) == item_category:
                 if ucat.pop(item_name, None) is not None:
                     # Only update the user_cats when something changes
-                    user_cats[k] = list([(n, c, 0) for n, c in ucat.items()])
+                    user_cats[k] = [(n, c, 0) for n, c in ucat.items()]
             elif ucat.get(item_name, None) == item_category:
                 # If the old name/item_category exists, rename it to the new
                 # name using del/add
                 del ucat[item_name]
                 ucat[new_name] = item_category
-                user_cats[k] = list([(n, c, 0) for n, c in ucat.items()])
+                user_cats[k] = [(n, c, 0) for n, c in ucat.items()]
         self.db.new_api.set_pref('user_categories', user_cats)
 
     def delete_item_from_all_user_categories(self, item_name, item_category):

src/calibre/gui2/tag_browser/ui.py

@@ -105,7 +105,7 @@ class TagBrowserMixin:  # {{{
                     proxy_md = db.new_api.get_proxy_metadata(db.id(idx.row()))
                     items = proxy_md.get(current_cat)
                     if isinstance(items, str):
-                        items = list((items,))
+                        items = [items,]
                     if items:
                         items_title = _('{category} for current book').format(category=cdn)
                         if len(items) > 4:

src/calibre/library/catalogs/epub_mobi.py

@@ -201,7 +201,7 @@ class EPUB_MOBI(CatalogPlugin):
             if opts.preset not in available_presets:
                 if available_presets:
                     print(_('Error: Preset "{}" not found.').format(opts.preset))
-                    print(_('Stored presets: {}').format(', '.join([p for p in sorted(available_presets.keys())])))
+                    print(_('Stored presets: {}').format(', '.join(list(sorted(available_presets.keys())))))
                 else:
                     print(_('Error: No stored presets.'))
                 return 1

src/calibre/library/catalogs/epub_mobi_builder.py

@@ -547,7 +547,7 @@ class CatalogBuilder:
          AuthorSortMismatchException: author_sort mismatch detected
         '''
 
-        books_by_author = sorted(list(books_to_test), key=self._kf_books_by_author_sorter_author)
+        books_by_author = sorted(books_to_test, key=self._kf_books_by_author_sorter_author)
 
         authors = [(record['author'], record['author_sort']) for record in books_by_author]
         current_author = authors[0]

src/calibre/utils/bibtex.py

@@ -2603,7 +2603,7 @@ class BibTeX:
         '''
         Format authors for Bibtex compliance (get a list as input)
         '''
-        return self.utf8ToBibtex(' and '.join([author for author in item]))
+        return self.utf8ToBibtex(' and '.join(list(item)))
 
     def stripUnmatchedSyntax(self, text, open_character, close_character):
         '''

src/calibre/utils/fonts/sfnt/subset.py

@@ -254,7 +254,7 @@ def main(args):
     with open(iff, 'rb') as f:
         orig = f.read()
 
-    chars = [x for x in chars.split(',')]
+    chars = list(chars.split(','))
     individual, ranges = set(), set()
 
     def not_single(c):

src/calibre/utils/formatter.py

@@ -878,11 +878,11 @@ class PythonTemplateContext:
     @property
     def attributes(self):
         # return a list of attributes in the context object
-        return sorted(list(self.attrs_set))
+        return sorted(self.attrs_set)
 
     def __str__(self):
         # return a string of the attribute with values separated by newlines
-        attrs = sorted(list(self.attrs_set))
+        attrs = sorted(self.attrs_set)
         ans = OrderedDict()
         for k in attrs:
             ans[k] = getattr(self, k, None)

src/calibre/utils/formatter_functions.py

@@ -3169,7 +3169,7 @@ This function works only in the GUI and the content server.
             return '1' if note is not None else ''
         try:
             notes_for_book = db.items_with_notes_in_book(mi.id)
-            values = [v for v in notes_for_book.get(field_name, {}).values()]
+            values = list(notes_for_book.get(field_name, {}).values())
             return db.field_metadata[field_name]['is_multiple'].get('list_to_ui', ', ').join(values)
         except Exception as e:
             traceback.print_exc()

src/calibre/utils/winreg/dde.py

@@ -55,7 +55,7 @@ DML_ERRORS = {
 
     'UNFOUND_QUEUE_ID': (0x4011, 'An invalid transaction identifier was passed to a DDEML function. Once the application has returned from an XTYP_XACT_COMPLETE callback, the transaction identifier for that callback function is no longer valid.'),  # noqa: E501
 }
-DML_ERROR_TEXT = {code:text for (code, text) in itervalues(DML_ERRORS)}
+DML_ERROR_TEXT = dict(itervalues(DML_ERRORS))
 
 user32 = windll.user32