pep8

recipes/ba_herald.recipe

@@ -57,7 +57,7 @@ class BuenosAiresHerald(BasicNewsRecipe):
         for feedobj in lfeeds:
             feedtitle, feedurl = feedobj
             self.report_progress(0, ('Fetching feed') + ' %s...' %
-                                 (feedtitle if feedtitle else feedurl))
+                                 (feedtitle or feedurl))
             articles = []
             soup = self.index_to_soup(feedurl)
             for item in soup.findAll('div', attrs={'class': 'nota_texto_seccion'}):

recipes/bookforummagazine.recipe

@@ -43,7 +43,7 @@ class BookforumMagazine(BasicNewsRecipe):
 
     def parse_index(self):
         soup = self.index_to_soup(
-            _issue_url if _issue_url else 'https://www.bookforum.com/print'
+            _issue_url or 'https://www.bookforum.com/print'
         )
         meta_ele = soup.find('meta', property='og:title')
         if meta_ele:

recipes/el_mercurio_chile.recipe

@@ -52,7 +52,7 @@ class ElMercurio(BasicNewsRecipe):
         for feedobj in lfeeds:
             feedtitle, feedurl = feedobj
             self.report_progress(0, _('Fetching feed') + ' %s...' %
-                                 (feedtitle if feedtitle else feedurl))
+                                 (feedtitle or feedurl))
             articles = []
             soup = self.index_to_soup(feedurl)
             arts = soup.find('div', attrs={'id': 'caja_listado_noticia_todas'})

recipes/instapaper.recipe

@@ -91,7 +91,7 @@ class InstapaperRecipe(BasicNewsRecipe):
         lfeeds = self.get_feeds()
         for feedobj in lfeeds:
             feedtitle, feedurl = feedobj
-            self.report_progress(0, 'Fetching feed' + ' %s...' % (feedtitle if feedtitle else feedurl))
+            self.report_progress(0, 'Fetching feed' + ' %s...' % (feedtitle or feedurl))
             articles = []
             soup = self.index_to_soup(feedurl)
             for item in soup.findAll('a', attrs={'class': 'article_title'}):

recipes/revista_veintitres.recipe

@@ -69,7 +69,7 @@ class Veintitres(BasicNewsRecipe):
             self.report_progress(
                 0,
                 _('Fetching feed') + ' %s...' %
-                (feedtitle if feedtitle else feedurl)
+                (feedtitle or feedurl)
             )
             articles = []
             soup = self.index_to_soup(feedurl)

recipes/theprint.recipe

@@ -58,7 +58,7 @@ class ThePrint(BasicNewsRecipe):
                 ans[current_section].append({'title': title, 'url': url, 'description': desc})
         ret = []
         for sec in secs:
-            if sec in ('On Camera',):
+            if sec == 'On Camera':
                 continue
             arts = ans[sec]
             if arts:

setup/check.py

@@ -157,7 +157,7 @@ class UpgradeSourceCode(Command):
         files = []
         for f in os.listdir(os.path.dirname(os.path.abspath(__file__))):
             q = os.path.join('setup', f)
-            if f.endswith('.py') and f not in ('linux-installer.py',) and not os.path.isdir(q):
+            if f.endswith('.py') and f != 'linux-installer.py' and not os.path.isdir(q):
                 files.append(q)
         for path in checkable_python_files(self.SRC):
             q = path.replace(os.sep, '/')

src/calibre/ai/lm_studio/backend.py

@@ -39,7 +39,7 @@ def api_url(path: str = '', use_api_url: str | None = None) -> str:
     base = (pref('api_url') if use_api_url is None else use_api_url) or LMStudioAI.DEFAULT_URL
     purl = urlparse(base)
     # LM Studio typically mounts endpoints under /v1
-    base_path = purl.path if purl.path else '/v1'
+    base_path = purl.path or '/v1'
     if not base_path.endswith('/v1'):
         base_path = posixpath.join(base_path, 'v1')
 

src/calibre/db/__init__.py

@@ -110,7 +110,7 @@ def get_data_as_dict(self, prefix=None, authors_as_string=False, ids=None, conve
         x['id'] = db_id
         x['formats'] = []
         isbn = self.isbn(db_id, index_is_id=True)
-        x['isbn'] = isbn if isbn else ''
+        x['isbn'] = isbn or ''
         if not x['authors']:
             x['authors'] = _('Unknown')
         x['authors'] = [i.replace('|', ',') for i in x['authors'].split(',')]

src/calibre/db/tables.py

@@ -70,8 +70,7 @@ class Table:
             # Legacy
             self.unserialize = lambda x: x.replace('|', ',') if x else ''
             self.serialize = lambda x: x.replace(',', '|')
-        self.link_table = (link_table if link_table else
-                'books_{}_link'.format(self.metadata['table']))
+        self.link_table = (link_table or 'books_{}_link'.format(self.metadata['table']))
         if self.supports_notes and dt == 'rating':  # custom ratings table
             self.supports_notes = False
 

src/calibre/db/write.py

@@ -31,7 +31,7 @@ def single_text(x):
     if not isinstance(x, str):
         x = x.decode(preferred_encoding, 'replace')
     x = x.strip()
-    return x if x else None
+    return x or None
 
 
 series_index_pat = re.compile(r'(.*)\s+\[([.0-9]+)\]$')

src/calibre/devices/jetbook/driver.py

@@ -50,7 +50,7 @@ class JETBOOK(USBMS):
         fileext = os.path.splitext(os.path.basename(fname))[1]
         if fileext.lower() not in ('txt', 'pdf', 'fb2'):
             return fname
-        title = mi.title if mi.title else 'Unknown'
+        title = mi.title or 'Unknown'
         title = title.replace(' ', '_')
         au = mi.format_authors()
         if not au:

src/calibre/devices/paladin/driver.py

@@ -121,7 +121,7 @@ class PALADIN(USBMS):
                     time_offsets[offset] = time_offsets[offset] + 1
 
                 try:
-                    device_offset = max(time_offsets, key=lambda a: time_offsets.get(a))
+                    device_offset = max(time_offsets, key=time_offsets.get)
                     debug_print(f'Device Offset: {device_offset} ms')
                     self.device_offset = device_offset
                 except ValueError:

src/calibre/devices/prs505/sony_cache.py

@@ -658,7 +658,7 @@ class XMLCache:
             record.set('size', clean(str(os.stat(path).st_size)))
         except Exception:
             record.set('size', '0')
-        title = book.title if book.title else _('Unknown')
+        title = book.title or _('Unknown')
         record_set('title', title)
         ts = book.title_sort
         if not ts:

src/calibre/devices/prst1/driver.py

@@ -208,7 +208,7 @@ class PRST1(USBMS):
                     time_offsets[offset] = time_offsets[offset] + 1
 
                 try:
-                    device_offset = max(time_offsets, key=lambda a: time_offsets.get(a))
+                    device_offset = max(time_offsets, key=time_offsets.get)
                     debug_print(f'Device Offset: {device_offset} ms')
                     self.device_offset = device_offset
                 except ValueError:

src/calibre/devices/usbms/deviceconfig.py

@@ -46,8 +46,7 @@ class DeviceConfig:
     @classmethod
     def _default_save_template(cls):
         from calibre.library.save_to_disk import config
-        return cls.SAVE_TEMPLATE if cls.SAVE_TEMPLATE else \
-            config().parse().send_template
+        return cls.SAVE_TEMPLATE or config().parse().send_template
 
     @classmethod
     def _config_base_name(cls):

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

@@ -260,7 +260,7 @@ class HTMLInput(InputFormatPlugin):
             link_ = link_.lstrip('/')
             base = self.root_dir_for_absolute_links
         try:
-            l = Link(link_, base if base else os.getcwd())
+            l = Link(link_, base or os.getcwd())
         except Exception:
             self.log.exception(f'Failed to process link: {link_!r}')
             return None, None

src/calibre/ebooks/conversion/preprocess.py

@@ -429,9 +429,9 @@ def book_designer_rules():
         lambda match : '<span style="page-break-after:always"> </span>'),
         # Create header tags
         (re.compile(r'<h2[^><]*?id=BookTitle[^><]*?(align=)*(?(1)(\w+))*[^><]*?>[^><]*?</h2>', re.IGNORECASE),
-        lambda match : '<h1 id="BookTitle" align="{}">{}</h1>'.format(match.group(2) if match.group(2) else 'center', match.group(3))),
+        lambda match : '<h1 id="BookTitle" align="{}">{}</h1>'.format(match.group(2) or 'center', match.group(3))),
         (re.compile(r'<h2[^><]*?id=BookAuthor[^><]*?(align=)*(?(1)(\w+))*[^><]*?>[^><]*?</h2>', re.IGNORECASE),
-        lambda match : '<h2 id="BookAuthor" align="{}">{}</h2>'.format(match.group(2) if match.group(2) else 'center', match.group(3))),
+        lambda match : '<h2 id="BookAuthor" align="{}">{}</h2>'.format(match.group(2) or 'center', match.group(3))),
         (re.compile(r'<span[^><]*?id=title[^><]*?>(.*?)</span>', re.IGNORECASE|re.DOTALL),
         lambda match : f'<h2 class="title">{match.group(1)}</h2>'),
         (re.compile(r'<span[^><]*?id=subtitle[^><]*?>(.*?)</span>', re.IGNORECASE|re.DOTALL),

src/calibre/ebooks/epub/periodical.py

@@ -166,7 +166,7 @@ def sony_metadata(oeb):
                 atitle = btitle + ' ' + str(d)
                 d += 1
 
-            auth = article.author if article.author else ''
+            auth = article.author or ''
             desc = section.description
             if not desc:
                 desc = ''

src/calibre/ebooks/htmlz/oeb2html.py

@@ -274,7 +274,7 @@ class OEB2HTMLInlineCSSizer(OEB2HTML):
         attribs = elem.attrib
 
         style_a = f'{style}'
-        style_a = style_a if style_a else ''
+        style_a = style_a or ''
         if tag == 'body':
             # Change the body to a div so we can merge multiple files.
             tag = 'div'

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

@@ -167,9 +167,9 @@ class HTMLConverter:
                       lambda match : '<span style="page-break-after:always"> </span>'),
                      # Create header tags
                      (re.compile(r'<h2[^><]*?id=BookTitle[^><]*?(align=)*(?(1)(\w+))*[^><]*?>[^><]*?</h2>', re.IGNORECASE),
-                      lambda match : '<h1 id="BookTitle" align="{}">{}</h1>'.format(match.group(2) if match.group(2) else 'center', match.group(3))),
+                      lambda match : '<h1 id="BookTitle" align="{}">{}</h1>'.format(match.group(2) or 'center', match.group(3))),
                      (re.compile(r'<h2[^><]*?id=BookAuthor[^><]*?(align=)*(?(1)(\w+))*[^><]*?>[^><]*?</h2>', re.IGNORECASE),
-                      lambda match : '<h2 id="BookAuthor" align="{}">{}</h2>'.format(match.group(2) if match.group(2) else 'center', match.group(3))),
+                      lambda match : '<h2 id="BookAuthor" align="{}">{}</h2>'.format(match.group(2) or 'center', match.group(3))),
                      (re.compile(r'<span[^><]*?id=title[^><]*?>(.*?)</span>', re.IGNORECASE|re.DOTALL),
                       lambda match : f'<h2 class="title">{match.group(1)}</h2>'),
                      (re.compile(r'<span[^><]*?id=subtitle[^><]*?>(.*?)</span>', re.IGNORECASE|re.DOTALL),
@@ -683,7 +683,7 @@ class HTMLConverter:
             if not item.fragment and item.abspath in self.tops:
                 self.book.addTocEntry(ascii_text, self.tops[item.abspath])
             elif item.abspath:
-                url = item.abspath+(item.fragment if item.fragment else '')
+                url = item.abspath+(item.fragment or '')
                 if url in self.targets:
                     self.book.addTocEntry(ascii_text, self.targets[url])
 
@@ -1715,7 +1715,7 @@ class HTMLConverter:
                 if tag.has_attr('color'):
                     tag_css['color'] = tag['color']
                 self.process_children(tag, tag_css, tag_pseudo_css)
-            elif tagname in ['br']:
+            elif tagname == 'br':
                 self.line_break()
                 self.previous_text = '\n'
             elif tagname in ['hr', 'tr']:  # tr needed for nested tables

src/calibre/ebooks/lrf/input.py

@@ -191,8 +191,8 @@ class TextBlock(etree.XSLTExtension):
             pidx = gp.index(p)
             children = list(p)[idx:]
             t = children[-1].tail
-            t = t if t else ''
-            children[-1].tail = t + (p.tail if p.tail else '')
+            t = t or ''
+            children[-1].tail = t + (p.tail or '')
             p.tail = ''
             pattrib = dict(**p.attrib) if p.tag == 'Span' else {}
             for child in children:

src/calibre/ebooks/lrf/pylrs/pylrs.py

@@ -1695,7 +1695,7 @@ class Plot(LrsSimpleChar1, LrsContainer):
         return elem
 
     def toLrfContainer(self, lrfWriter, parent):
-        adj = self.adjustment if self.adjustment else 'bottom'
+        adj = self.adjustment or 'bottom'
         params = (int(self.xsize), int(self.ysize), int(self.obj.objId),
                   Plot.ADJUSTMENT_VALUES[adj])
         parent.appendLrfTag(LrfTag('Plot', params))

src/calibre/ebooks/metadata/ereader.py

@@ -56,7 +56,7 @@ def get_metadata(stream, extract_cover=True):
                 mi.cover_data = get_cover(pheader, hr)
 
     if not mi.title:
-        mi.title = pheader.title if pheader.title else _('Unknown')
+        mi.title = pheader.title or _('Unknown')
 
     return mi
 

src/calibre/ebooks/metadata/html.py

@@ -315,7 +315,7 @@ class MetadataHtmlTest(unittest.TestCase):
         <!-- TAGS="tag d" -->
 '''
 
-        if test in {'comment_multi'}:
+        if test == 'comment_multi':
             raw += b'''\
         <!-- TITLE="Another Comment Tag &amp;amp; Title &#9400;" -->
         <!-- AUTHOR="John Quincy Adams" -->

src/calibre/ebooks/metadata/mobi.py

@@ -262,7 +262,7 @@ class MetadataUpdater:
         new_record0.write(exth)
         if self.encryption_type != 0:
             new_record0.write(self.drm_block)
-        new_record0.write(new_title if new_title else title_in_file)
+        new_record0.write(new_title or title_in_file)
 
         # Pad to a 4-byte boundary
         trail = len(new_record0.getvalue()) % 4

src/calibre/ebooks/metadata/opf2.py

@@ -420,7 +420,7 @@ class Guide(ResourceCollection):  # {{{
 class MetadataField:
 
     def __init__(self, name, is_dc=True, formatter=None, none_is=None,
-            renderer=lambda x: str(x)):
+            renderer=str):
         self.name      = name
         self.is_dc     = is_dc
         self.formatter = formatter
@@ -1536,7 +1536,7 @@ class OPFCreator(Metadata):
         metadata = M.metadata()
         a = metadata.append
         role = {}
-        a(DC_ELEM('title', self.title if self.title else _('Unknown'),
+        a(DC_ELEM('title', self.title or _('Unknown'),
             opf_attrs=role))
         for i, author in enumerate(self.authors):
             fa = {'role':'aut'}

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

@@ -181,7 +181,7 @@ class ISBNMerge:
         # First title/author
         groups = {}
         for result in self.results:
-            title = lower(result.title if result.title else '')
+            title = lower(result.title or '')
             key = (title, tuple(lower(x) for x in result.authors))
             if key not in groups:
                 groups[key] = []

src/calibre/ebooks/mobi/debug/mobi6.py

@@ -516,8 +516,7 @@ class FontRecord:  # {{{
         if self.font['err']:
             raise ValueError('Failed to read font record: {} Headers: {}'.format(
                 self.font['err'], self.font['headers']))
-        self.payload = (self.font['font_data'] if self.font['font_data'] else
-                self.font['raw_data'])
+        self.payload = (self.font['font_data'] or self.font['raw_data'])
         self.name = '{}.{}'.format(name, self.font['ext'])
 
     def dump(self, folder):

src/calibre/ebooks/mobi/debug/mobi8.py

@@ -184,8 +184,7 @@ class MOBIFile:
                 if font['err']:
                     raise ValueError('Failed to read font record: {} Headers: {}'.format(
                         font['err'], font['headers']))
-                payload = (font['font_data'] if font['font_data'] else
-                        font['raw_data'])
+                payload = (font['font_data'] or font['raw_data'])
                 prefix, ext = 'fonts', font['ext']
             elif sig == b'CONT':
                 if payload == b'CONTBOUNDARY':

src/calibre/ebooks/mobi/reader/mobi8.py

@@ -173,7 +173,7 @@ class Mobi8Reader:
         raw_ml = self.mobi6_reader.mobi_html
         self.flows = []
         self.flowinfo = []
-        ft = self.flow_table if self.flow_table else [(0, len(raw_ml))]
+        ft = self.flow_table or [(0, len(raw_ml))]
 
         # now split the raw_ml into its flow pieces
         for start, end in ft:
@@ -434,8 +434,7 @@ class Mobi8Reader:
                         if font['headers']:
                             self.log.debug('Font record headers: {}'.format(font['headers']))
                     with open(href.replace('/', os.sep), 'wb') as f:
-                        f.write(font['font_data'] if font['font_data'] else
-                                font['raw_data'])
+                        f.write(font['font_data'] or font['raw_data'])
                     if font['encrypted']:
                         self.encrypted_fonts.append(href)
                 elif typ == b'CONT':

src/calibre/ebooks/mobi/writer2/main.py

@@ -288,7 +288,7 @@ class MobiWriter:
         # 0x58 - 0x5b : Format version
         # 0x5c - 0x5f : First image record number
         record0.write(pack(b'>II',
-            6, first_image_record if first_image_record else len(self.records)))
+            6, first_image_record or len(self.records)))
 
         # 0x60 - 0x63 : First HUFF/CDIC record number
         # 0x64 - 0x67 : Number of HUFF/CDIC records
@@ -400,8 +400,7 @@ class MobiWriter:
         self.records.append(self.kf8.record0)
         self.records.extend(self.kf8.records[1:])
 
-        first_image_record = (first_image_record if first_image_record else
-                len(self.records))
+        first_image_record = (first_image_record or len(self.records))
 
         header_fields = {k:getattr(self.kf8, k) for k in HEADER_FIELDS}
 

src/calibre/ebooks/mobi/writer8/main.py

@@ -116,7 +116,7 @@ class KF8Writer:
             ref = urlnormalize(item.abshref(oref))
             idx = self.resources.item_map.get(ref, None)
             if idx is not None:
-                is_image = self.resources.records[idx-1][:4] not in {b'FONT'}
+                is_image = self.resources.records[idx-1][:4] != b'FONT'
                 idx = to_ref(idx)
                 if is_image:
                     self.used_images.add(ref)

src/calibre/ebooks/oeb/stylizer.py

@@ -266,7 +266,7 @@ class Stylizer:
                 log=logging.getLogger('calibre.css'))
         for elem in style_tags:
             if (elem.tag in (XHTML('style'), SVG('style')) and elem.get('type', CSS_MIME) in OEB_STYLES and media_ok(elem.get('media'))):
-                text = elem.text if elem.text else ''
+                text = elem.text or ''
                 for x in elem:
                     t = getattr(x, 'text', None)
                     if t:
@@ -614,7 +614,7 @@ class Style:
                 self._bgcolor = False
             else:
                 self._bgcolor = col
-        return self._bgcolor if self._bgcolor else None
+        return self._bgcolor or None
 
     @property
     def fontSize(self):

src/calibre/ebooks/oeb/transforms/jacket.py

@@ -312,9 +312,9 @@ def render_jacket(mi, output_profile,
 
     rating = get_rating(mi.rating, output_profile.ratings_char, output_profile.empty_ratings_char)
 
-    tags = Tags((mi.tags if mi.tags else alt_tags), output_profile)
+    tags = Tags((mi.tags or alt_tags), output_profile)
 
-    comments = mi.comments if mi.comments else alt_comments
+    comments = mi.comments or alt_comments
     comments = comments.strip()
     if comments:
         comments = comments_to_html(comments)

src/calibre/ebooks/oeb/transforms/split.py

@@ -200,7 +200,7 @@ class Split:
             return url
         if href in self.map:
             anchor_map = self.map[href]
-            nhref = anchor_map[frag if frag else None]
+            nhref = anchor_map[frag or None]
             nhref = self.current_item.relhref(nhref)
             if frag:
                 nhref = '#'.join((unquote(nhref), frag))
@@ -478,7 +478,7 @@ class FlowSplitter:
             for ref in self.oeb.guide.values():
                 href, frag = urldefrag(ref.href)
                 if href == self.item.href:
-                    nhref = self.anchor_map[frag if frag else None]
+                    nhref = self.anchor_map[frag or None]
                     if frag:
                         nhref = '#'.join((nhref, frag))
                     ref.href = nhref
@@ -487,7 +487,7 @@ class FlowSplitter:
             if toc.href:
                 href, frag = urldefrag(toc.href)
                 if href == self.item.href:
-                    nhref = self.anchor_map[frag if frag else None]
+                    nhref = self.anchor_map[frag or None]
                     if frag:
                         nhref = '#'.join((nhref, frag))
                     toc.href = nhref
@@ -501,7 +501,7 @@ class FlowSplitter:
             for page in self.oeb.pages:
                 href, frag = urldefrag(page.href)
                 if href == self.item.href:
-                    nhref = self.anchor_map[frag if frag else None]
+                    nhref = self.anchor_map[frag or None]
                     if frag:
                         nhref = '#'.join((nhref, frag))
                     page.href = nhref

src/calibre/ebooks/oeb/transforms/structure.py

@@ -74,8 +74,7 @@ class DetectStructure:
             regexp = re.compile(opts.toc_filter)
             for node in list(self.oeb.toc.iter()):
                 if not node.title or regexp.search(node.title) is not None:
-                    self.log('Filtering', node.title if node.title else
-                            'empty node', 'from TOC')
+                    self.log('Filtering', node.title or 'empty node', 'from TOC')
                     self.oeb.toc.remove(node)
 
         if opts.page_breaks_before is not None:

src/calibre/ebooks/pdb/palmdoc/writer.py

@@ -25,7 +25,7 @@ class Writer(FormatWriter):
     def write_content(self, oeb_book, out_stream, metadata=None):
         from calibre.ebooks.compression.palmdoc import compress_doc
 
-        title = self.opts.title if self.opts.title else oeb_book.metadata.title[0].value if oeb_book.metadata.title != [] else _('Unknown')
+        title = self.opts.title or (oeb_book.metadata.title[0].value if oeb_book.metadata.title != [] else _('Unknown'))
 
         txt_records, txt_length = self._generate_text(oeb_book)
         header_record = self._header_record(txt_length, len(txt_records))

src/calibre/ebooks/pdb/ztxt/writer.py

@@ -24,7 +24,7 @@ class Writer(FormatWriter):
         self.log = log
 
     def write_content(self, oeb_book, out_stream, metadata=None):
-        title = self.opts.title if self.opts.title else oeb_book.metadata.title[0].value if oeb_book.metadata.title != [] else _('Unknown')
+        title = self.opts.title or (oeb_book.metadata.title[0].value if oeb_book.metadata.title != [] else _('Unknown'))
 
         txt_records, txt_length = self._generate_text(oeb_book)
 

src/calibre/ebooks/pdf/html_writer.py

@@ -341,7 +341,7 @@ class RequestInterceptor(QWebEngineUrlRequestInterceptor):
             request_info.block(True)
             return
         qurl = request_info.requestUrl()
-        if qurl.scheme() not in (FAKE_PROTOCOL,):
+        if qurl.scheme() != FAKE_PROTOCOL:
             self.log.warn(f'Blocking URL request {qurl.toString()} as it is not for a resource in the book')
             request_info.block(True)
             return

src/calibre/ebooks/render_html.py

@@ -38,7 +38,7 @@ class RequestInterceptor(QWebEngineUrlRequestInterceptor):
             request_info.block(True)
             return
         qurl = request_info.requestUrl()
-        if qurl.scheme() not in (FAKE_PROTOCOL,):
+        if qurl.scheme() != FAKE_PROTOCOL:
             default_log.warn(f'Blocking URL request {qurl.toString()} as it is not for a resource related to the HTML file being rendered')
             request_info.block(True)
             return

src/calibre/gui2/actions/__init__.py

@@ -234,12 +234,12 @@ class InterfaceAction(QObject):
             ma.triggered.connect(action.trigger)
         for a in ((action, ma) if attr == 'qaction' else (action,)):
             a.setAutoRepeat(self.auto_repeat)
-            text = tooltip if tooltip else text
+            text = tooltip or text
             a.setToolTip(text)
             a.setStatusTip(text)
             a.setWhatsThis(text)
         shortcut_action = action
-        desc = tooltip if tooltip else None
+        desc = tooltip or None
         if attr == 'qaction':
             shortcut_action = ma
         if shortcut is not None:

src/calibre/gui2/actions/choose_library.py

@@ -553,10 +553,10 @@ class ChooseLibraryAction(InterfaceAction):
         restrictions.insert(0, '')
         for vl in restrictions:
             if vl == vl_at_startup:
-                self.vl_to_apply_menu.addAction(QIcon.ic('ok.png'), vl if vl else _('No Virtual library'),
+                self.vl_to_apply_menu.addAction(QIcon.ic('ok.png'), vl or _('No Virtual library'),
                                                 Dispatcher(partial(self.change_vl_at_startup_requested, vl)))
             else:
-                self.vl_to_apply_menu.addAction(vl if vl else _('No Virtual library'),
+                self.vl_to_apply_menu.addAction(vl or _('No Virtual library'),
                                                 Dispatcher(partial(self.change_vl_at_startup_requested, vl)))
         # Allow the cloned actions in the OS X global menubar to update
         for a in (self.qaction, self.menuless_qaction):

src/calibre/gui2/actions/mark_books.py

@@ -237,7 +237,7 @@ class MarkBooksAction(InterfaceActionWithLibraryDrop):
         if dialog.exec_() != QDialog.DialogCode.Accepted:
             return
         txt = dialog.text()
-        txt = txt if txt else 'true'
+        txt = txt or 'true'
         db = self.gui.current_db
         mids = db.data.marked_ids.copy()
         for book_id in book_ids:

src/calibre/gui2/catalog/catalog_epub_mobi.py

@@ -350,10 +350,10 @@ class PluginWidget(QWidget, Ui_Form):
         for opt in self.OPTION_FIELDS:
             c_name, c_def, c_type = opt
             opt_value = gprefs.get(self.name + '_' + c_name, c_def)
-            if c_type in ['check_box']:
+            if c_type == 'check_box':
                 getattr(self, c_name).setChecked(eval(str(opt_value)))
                 getattr(self, c_name).clicked.connect(partial(self.settings_changed, c_name))
-            elif c_type in ['combo_box']:
+            elif c_type == 'combo_box':
                 if opt_value is None:
                     index = 0
                     if c_name == 'genre_source_field':
@@ -368,13 +368,13 @@ class PluginWidget(QWidget, Ui_Form):
                 getattr(self, c_name).setCurrentIndex(index)
                 if c_name != 'preset_field':
                     getattr(self, c_name).currentIndexChanged.connect(partial(self.settings_changed, c_name))
-            elif c_type in ['line_edit']:
-                getattr(self, c_name).setText(opt_value if opt_value else '')
+            elif c_type == 'line_edit':
+                getattr(self, c_name).setText(opt_value or '')
                 getattr(self, c_name).editingFinished.connect(partial(self.settings_changed, c_name))
-            elif c_type in ['radio_button'] and opt_value is not None:
+            elif c_type == 'radio_button' and opt_value is not None:
                 getattr(self, c_name).setChecked(opt_value)
                 getattr(self, c_name).clicked.connect(partial(self.settings_changed, c_name))
-            elif c_type in ['spin_box']:
+            elif c_type == 'spin_box':
                 getattr(self, c_name).setValue(float(opt_value))
                 getattr(self, c_name).valueChanged.connect(partial(self.settings_changed, c_name))
             if c_type == 'table_widget':
@@ -480,13 +480,13 @@ class PluginWidget(QWidget, Ui_Form):
 
             if c_type in ['check_box', 'radio_button']:
                 opt_value = getattr(self, c_name).isChecked()
-            elif c_type in ['combo_box']:
+            elif c_type == 'combo_box':
                 opt_value = str(getattr(self, c_name).currentText()).strip()
-            elif c_type in ['line_edit']:
+            elif c_type == 'line_edit':
                 opt_value = str(getattr(self, c_name).text()).strip()
-            elif c_type in ['spin_box']:
+            elif c_type == 'spin_box':
                 opt_value = str(getattr(self, c_name).value())
-            elif c_type in ['table_widget']:
+            elif c_type == 'table_widget':
                 if c_name == 'prefix_rules_tw':
                     opt_value = self.prefix_rules_table.get_data()
                     prefix_rules_processed = True
@@ -652,11 +652,11 @@ class PluginWidget(QWidget, Ui_Form):
                 opt_value = options[c_name]
             else:
                 continue
-            if c_type in ['check_box']:
+            if c_type == 'check_box':
                 getattr(self, c_name).setChecked(eval(str(opt_value)))
                 if c_name == 'generate_genres':
                     self.genre_source_field.setEnabled(eval(str(opt_value)))
-            elif c_type in ['combo_box']:
+            elif c_type == 'combo_box':
                 if opt_value is None:
                     index = 0
                     if c_name == 'genre_source_field':
@@ -669,11 +669,11 @@ class PluginWidget(QWidget, Ui_Form):
                         elif c_name == 'genre_source_field':
                             index = self.genre_source_field.findText(_('Tags'))
                 getattr(self, c_name).setCurrentIndex(index)
-            elif c_type in ['line_edit']:
-                getattr(self, c_name).setText(opt_value if opt_value else '')
-            elif c_type in ['radio_button'] and opt_value is not None:
+            elif c_type == 'line_edit':
+                getattr(self, c_name).setText(opt_value or '')
+            elif c_type == 'radio_button' and opt_value is not None:
                 getattr(self, c_name).setChecked(opt_value)
-            elif c_type in ['spin_box']:
+            elif c_type == 'spin_box':
                 getattr(self, c_name).setValue(float(opt_value))
             if c_type == 'table_widget':
                 if c_name == 'exclusion_rules_tw':
@@ -765,15 +765,15 @@ class PluginWidget(QWidget, Ui_Form):
 
             if c_type in ['check_box', 'radio_button']:
                 opt_value = getattr(self, c_name).isChecked()
-            elif c_type in ['combo_box']:
+            elif c_type == 'combo_box':
                 if c_name == 'preset_field':
                     continue
                 opt_value = str(getattr(self, c_name).currentText()).strip()
-            elif c_type in ['line_edit']:
+            elif c_type == 'line_edit':
                 opt_value = str(getattr(self, c_name).text()).strip()
-            elif c_type in ['spin_box']:
+            elif c_type == 'spin_box':
                 opt_value = str(getattr(self, c_name).value())
-            elif c_type in ['table_widget']:
+            elif c_type == 'table_widget':
                 if c_name == 'prefix_rules_tw':
                     opt_value = self.prefix_rules_table.get_data()
                     prefix_rules_processed = True
@@ -1024,7 +1024,7 @@ class GenericRulesTable(QTableWidget):
             self.select_and_scroll_to_row(first_sel_row - 1)
 
     def enabled_state_changed(self, row, col):
-        if col in [self.COLUMNS['ENABLED']['ordinal']]:
+        if col == self.COLUMNS['ENABLED']['ordinal']:
             self.select_and_scroll_to_row(row)
             self.settings_changed('enabled_state_changed')
             if self.DEBUG:
@@ -1165,11 +1165,11 @@ class GenericRulesTable(QTableWidget):
             values = self.db.all_custom(self.db.field_metadata.key_to_label(
                                         self.eligible_custom_fields[str(source_field)]['field']))
             values = sorted(values, key=sort_key)
-        elif self.eligible_custom_fields[str(source_field)]['datatype'] in ['bool']:
+        elif self.eligible_custom_fields[str(source_field)]['datatype'] == 'bool':
             values = [_('True'),_('False'),_('unspecified')]
-        elif self.eligible_custom_fields[str(source_field)]['datatype'] in ['composite']:
+        elif self.eligible_custom_fields[str(source_field)]['datatype'] == 'composite':
             values = [_('any value'),_('unspecified')]
-        elif self.eligible_custom_fields[str(source_field)]['datatype'] in ['datetime']:
+        elif self.eligible_custom_fields[str(source_field)]['datatype'] == 'datetime':
             values = [_('any date'),_('unspecified')]
 
         values_combo = ComboBox(self, values, pattern)

src/calibre/gui2/comments_editor.py

@@ -894,7 +894,7 @@ class EditorWidget(QTextEdit, LineEditECM):  # {{{
                 if data_dir:
                     path = os.path.relpath(path, base).replace(os.sep, '/')
                     d.url.setText(path)
-        b.clicked.connect(lambda: cf())
+        b.clicked.connect(cf)
         d.brdf = b = QPushButton(_('&Data file'))
         b.clicked.connect(lambda: cf(True))
         b.setToolTip(_('A relative link to a data file associated with this book'))

src/calibre/gui2/convert/__init__.py

@@ -189,9 +189,9 @@ class Widget(QWidget):
         elif isinstance(g, QCheckBox):
             return bool(g.isChecked())
         elif isinstance(g, XPathEdit):
-            return g.xpath if g.xpath else None
+            return g.xpath or None
         elif isinstance(g, RegexEdit):
-            return g.regex if g.regex else None
+            return g.regex or None
         else:
             raise Exception(f"Can't get value from {type(g)}")
 
@@ -261,7 +261,7 @@ class Widget(QWidget):
         elif isinstance(g, QCheckBox):
             g.setCheckState(Qt.CheckState.Checked if bool(val) else Qt.CheckState.Unchecked)
         elif isinstance(g, (XPathEdit, RegexEdit)):
-            g.edit.setText(val if val else '')
+            g.edit.setText(val or '')
         else:
             raise Exception(f"Can't set value {val!r} in {g.objectName()!s}")
         self.post_set_value(g, val)

src/calibre/gui2/convert/metadata.py

@@ -90,15 +90,15 @@ class MetadataWidget(Widget, Ui_Form):
 
         mi = self.db.get_metadata(self.book_id, index_is_id=True)
         self.title.setText(mi.title), self.title.home(False)
-        self.publisher.show_initial_value(mi.publisher if mi.publisher else '')
+        self.publisher.show_initial_value(mi.publisher or '')
         self.publisher.home(False)
-        self.author_sort.setText(mi.author_sort if mi.author_sort else '')
+        self.author_sort.setText(mi.author_sort or '')
         self.author_sort.home(False)
-        self.tags.setText(', '.join(mi.tags if mi.tags else []))
+        self.tags.setText(', '.join(mi.tags or []))
         self.tags.update_items_cache(self.db.new_api.all_field_names('tags'))
         self.tags.home(False)
         self.comment.html = comments_to_html(mi.comments) if mi.comments else ''
-        self.series.show_initial_value(mi.series if mi.series else '')
+        self.series.show_initial_value(mi.series or '')
         self.series.home(False)
         if mi.series_index is not None:
             try:

src/calibre/gui2/convert/search_and_replace.py

@@ -267,7 +267,7 @@ class SearchAndReplaceWidget(Widget, Ui_Form):
                 if name in getattr(recs, 'disabled_options', []):
                     self.search_replace.setDisabled(True)
             elif name.startswith('sr'):
-                legacy[name] = val if val else ''
+                legacy[name] = val or ''
             else:
                 rest[name] = val
 

src/calibre/gui2/device.py

@@ -1118,8 +1118,7 @@ class DeviceMixin:  # {{{
             func = {UserFeedback.ERROR:error_dialog,
                     UserFeedback.WARNING:warning_dialog,
                     UserFeedback.INFO:info_dialog}[ex.level]
-            return func(self, _('Failed'), ex.msg, det_msg=ex.details if
-                    ex.details else '', show=True)
+            return func(self, _('Failed'), ex.msg, det_msg=ex.details or '', show=True)
 
         try:
             if 'Could not read 32 bytes on the control bus.' in \

src/calibre/gui2/dialogs/metadata_bulk.py

@@ -555,12 +555,13 @@ class MyBlockingBusy(QDialog):  # {{{
 
 class MetadataBulkDialog(QDialog, Ui_MetadataBulkDialog):
 
-    s_r_functions = {'': lambda x: x,
-        _('Lower Case'): lambda x: icu_lower(x),
-        _('Upper Case'): lambda x: icu_upper(x),
-        _('Title Case'): lambda x: titlecase(x),
-        _('Capitalize'): lambda x: capitalize(x),
-                    }
+    s_r_functions = {
+        '': lambda x: x,
+        _('Lower Case'): icu_lower,
+        _('Upper Case'): icu_upper,
+        _('Title Case'): titlecase,
+        _('Capitalize'): capitalize,
+    }
 
     s_r_match_modes = [_('Character match'),
                             _('Regular expression'),
@@ -784,7 +785,7 @@ class MetadataBulkDialog(QDialog, Ui_MetadataBulkDialog):
         self.writable_fields = ['']
         fm = self.db.field_metadata
         for f in fm:
-            if (f in ['author_sort'] or
+            if (f == 'author_sort' or
                     (fm[f]['datatype'] in ['text', 'series', 'enumeration', 'comments', 'rating'] and
                      fm[f].get('search_terms', None) and
                      f not in ['formats', 'ondevice', 'series_sort', 'in_tag_browser']) or

src/calibre/gui2/dialogs/quickview.py

@@ -312,7 +312,7 @@ class Quickview(QDialog, Ui_Quickview):
         if not self.is_pane:
             if toggle_shortcut and self.close_button.shortcut() != toggle_shortcut:
                 toggle_sc = QShortcut(toggle_shortcut, self.close_button)
-                toggle_sc.activated.connect(lambda: self.close_button_clicked())
+                toggle_sc.activated.connect(self.close_button_clicked)
                 toggle_sc.setEnabled(True)
                 self.close_button.setToolTip(_('Alternate shortcut: ') +
                                              toggle_shortcut.toString())

src/calibre/gui2/dialogs/search.py

@@ -402,9 +402,12 @@ class SearchDialog(QDialog):
         else:
             self.copy_current_template_search_button.setEnabled(False)
         self.copy_current_template_search_button.clicked.connect(self.retrieve_template_search)
-        self.edit_template_button.clicked.connect(lambda: self.template_program_box.open_editor())
+        self.edit_template_button.clicked.connect(self.open_template_program_box_editor)
         self.resize(self.sizeHint())
 
+    def open_template_program_box_editor(self):
+        self.template_program_box.open_editor()
+
     def retrieve_template_search(self):
         template, sep, query = re.split(r'#@#:([tdnb]):', self.current_search_text, flags=re.IGNORECASE)
         self.template_value_box.setText(query)

src/calibre/gui2/dialogs/template_dialog.py

@@ -254,8 +254,7 @@ class TemplateHighlighter(QSyntaxHighlighter):
             a(r'^program:', 'keymode')
             a('|'.join([rf'\b{keyword}\b' for keyword in self.KEYWORDS_GPM]), 'keyword')
             a('|'.join([rf'\b{builtin}\b' for builtin in
-                            (builtin_functions if builtin_functions else
-                                                formatter_functions().get_builtins())]),
+                            (builtin_functions or formatter_functions().get_builtins())]),
                 'builtin')
             a(r'''(?<!:)'[^']*'|"[^"]*\"''', 'string')
         else:
@@ -577,9 +576,8 @@ class TemplateDialog(QDialog, Ui_TemplateDialog):
 
         self.setup_saved_template_editor(not dialog_is_st_editor, dialog_is_st_editor)
 
-        self.all_functions = all_functions if all_functions else formatter_functions().get_functions()
-        self.builtins = (builtin_functions if builtin_functions else
-                         formatter_functions().get_builtins_and_aliases())
+        self.all_functions = all_functions or formatter_functions().get_functions()
+        self.builtins = (builtin_functions or formatter_functions().get_builtins_and_aliases())
 
         # Set up the breakpoint bar
         run_as_you_type = gprefs.get('template_editor_run_as_you_type')

src/calibre/gui2/metadata/bulk_download.py

@@ -95,7 +95,7 @@ class ConfirmDialog(QDialog):
         b.setIcon(QIcon.ic('default_cover.png'))
         b = self.b = self.bb.addButton(_('&Configure download'), QDialogButtonBox.ButtonRole.ActionRole)
         b.setIcon(QIcon.ic('config.png'))
-        connect_lambda(b.clicked, self, lambda self: show_config(self))
+        connect_lambda(b.clicked, self, lambda self: show_config(self))  # noqa: PLW0108
         l.addWidget(self.bb, 1, 0, 1, 2)
         b = self.bb.addButton(_('Download &both'),
                 QDialogButtonBox.ButtonRole.AcceptRole)

src/calibre/gui2/metadata/config.py

@@ -99,7 +99,7 @@ class ConfigWidget(QWidget):
             widget.setValue(val)
         elif opt.type == 'string':
             widget = QLineEdit(self)
-            widget.setText(val if val else '')
+            widget.setText(val or '')
         elif opt.type == 'bool':
             widget = QCheckBox(opt.label, self)
             widget.setChecked(bool(val))

src/calibre/gui2/metadata/single.py

@@ -560,7 +560,7 @@ class MetadataSingleDialogBase(QDialog):
             self.publisher.set_value(mi.publisher)
         if not mi.is_null('tags'):
             old_tags = self.tags.current_val
-            tags = mi.tags if mi.tags else []
+            tags = mi.tags or []
             if old_tags and merge_tags:
                 ltags, lotags = {t.lower() for t in tags}, {t.lower() for t in
                         old_tags}

src/calibre/gui2/metadata/single_download.py

@@ -178,12 +178,12 @@ class ResultsModel(QAbstractTableModel):  # {{{
         if col == 0:
             return str(book.gui_rank+1)
         if col == 1:
-            t = book.title if book.title else _('Unknown')
+            t = book.title or _('Unknown')
             a = authors_to_string(book.authors) if book.authors else ''
             return f'<b>{t}</b><br><i>{a}</i>'
         if col == 2:
             d = format_date(book.pubdate, 'yyyy') if book.pubdate else _('Unknown')
-            p = book.publisher if book.publisher else ''
+            p = book.publisher or ''
             return f'<b>{d}</b><br><i>{p}</i>'
 
     def data(self, index, role):

src/calibre/gui2/preferences/__init__.py

@@ -232,7 +232,7 @@ class Setting:
         elif self.datatype == 'number':
             self.gui_obj.setValue(val)
         elif self.datatype == 'string':
-            self.gui_obj.setText(val if val else '')
+            self.gui_obj.setText(val or '')
         elif self.datatype == 'choice':
             if isinstance(self.gui_obj, EditWithComplete):
                 self.gui_obj.setText(val)

src/calibre/gui2/preferences/main.py

@@ -190,8 +190,7 @@ class Browser(QScrollArea):  # {{{
                 category_map[plugin.category] = plugin.category_order
             category_map[plugin.category] = max(category_map[plugin.category], plugin.category_order)
             if plugin.category not in category_names:
-                category_names[plugin.category] = (plugin.gui_category if
-                    plugin.gui_category else plugin.category)
+                category_names[plugin.category] = (plugin.gui_category or plugin.category)
 
         self.category_names = category_names
 

src/calibre/gui2/preferences/template_functions.py

@@ -348,7 +348,7 @@ class ConfigWidget(ConfigWidgetBase, Ui_Form):
         return False
 
     def create_button_clicked(self, use_name=None, need_error_checks=True):
-        name = use_name if use_name else str(self.function_name.currentText())
+        name = use_name or str(self.function_name.currentText())
         name = name.split(' -- ')[0]
         if need_error_checks and self.check_errors_before_save(name, for_replace=False):
             return
@@ -526,7 +526,7 @@ class ConfigWidget(ConfigWidgetBase, Ui_Form):
 
     def st_create_button_clicked(self, use_name=None):
         self.changed_signal.emit()
-        name = use_name if use_name else str(self.te_name.currentText())
+        name = use_name or str(self.te_name.currentText())
         for k,v in formatter_functions().get_functions().items():
             if k == name and v.object_type is StoredObjectType.PythonFunction:
                 error_dialog(self.gui, _('Stored templates'),

src/calibre/gui2/pyqt6_compat.py

@@ -74,7 +74,7 @@ def set_menu(self, menu):
 
 
 QAction.setMenu = set_menu
-QAction.menu = lambda self: progress_indicator.menu_for_action(self)
+QAction.menu = lambda self: progress_indicator.menu_for_action(self)  # noqa: PLW0108
 
 
 # Restore QModelIndex::child

src/calibre/gui2/search_box.py

@@ -526,7 +526,7 @@ class SavedSearchBoxMixin:  # {{{
     def get_saved_search_text(self, search_name=None):
         db = self.current_db
         try:
-            current_search = search_name if search_name else self.search.currentText()
+            current_search = search_name or self.search.currentText()
             if not current_search.startswith('search:'):
                 raise ValueError()
             # This strange expression accounts for the four ways a search can be written:

src/calibre/gui2/search_restriction_mixin.py

@@ -625,9 +625,9 @@ class SearchRestrictionMixin:
             self.search_restriction.addItem(name)
             txt = self._trim_restriction_name(last)
             if compare_fix_amps(name, current_restriction):
-                a = current_menu.addAction(self.checked, txt if txt else self.no_restriction)
+                a = current_menu.addAction(self.checked, txt or self.no_restriction)
             else:
-                a = current_menu.addAction(txt if txt else self.no_restriction)
+                a = current_menu.addAction(txt or self.no_restriction)
             a.triggered.connect(partial(self.search_restriction_triggered, action=a, index=dex))
             dex += 1
             return a

src/calibre/gui2/store/opensearch_store.py

@@ -88,7 +88,7 @@ class OpenSearchOPDSStore(StorePlugin):
             return
 
         if external or self.config.get('open_external', False):
-            open_url(QUrl(detail_item if detail_item else self.web_url))
+            open_url(QUrl(detail_item or self.web_url))
         else:
             d = WebStoreDialog(self.gui, self.web_url, parent, detail_item, create_browser=self.create_browser)
             d.setWindowTitle(self.name)

src/calibre/gui2/store/search/models.py

@@ -202,8 +202,8 @@ class Matches(QAbstractItemModel):
         result = self.matches[row]
         if role == Qt.ItemDataRole.DisplayRole:
             if col == 1:
-                t = result.title if result.title else _('Unknown')
-                a = result.author if result.author else ''
+                t = result.title or _('Unknown')
+                a = result.author or ''
                 return (f'<b>{t}</b><br><i>{a}</i>')
             elif col == 2:
                 return (result.price)

src/calibre/gui2/store/stores/bn_plugin.py

@@ -91,7 +91,7 @@ class BNStore(BasicStoreConfig, StorePlugin):
         url = 'https://bn.com'
 
         if external or self.config.get('open_external', False):
-            open_url(QUrl(url_slash_cleaner(detail_item if detail_item else url)))
+            open_url(QUrl(url_slash_cleaner(detail_item or url)))
         else:
             d = WebStoreDialog(self.gui, url, parent, detail_item)
             d.setWindowTitle(self.name)

src/calibre/gui2/store/stores/bubok_portugal_plugin.py

@@ -34,7 +34,7 @@ class BubokPortugalStore(BasicStoreConfig, StorePlugin):
     def open(self, parent=None, detail_item=None, external=False):
         url = 'https://www.bubok.pt/tienda'
         if external or self.config.get('open_external', False):
-            open_url(QUrl(url_slash_cleaner(detail_item if detail_item else url)))
+            open_url(QUrl(url_slash_cleaner(detail_item or url)))
         else:
             d = WebStoreDialog(self.gui, url, parent, detail_item)
             d.setWindowTitle(self.name)

src/calibre/gui2/store/stores/bubok_publishing_plugin.py

@@ -34,7 +34,7 @@ class BubokPublishingStore(BasicStoreConfig, StorePlugin):
     def open(self, parent=None, detail_item=None, external=False):
         url = 'https://www.bubok.es/tienda'
         if external or self.config.get('open_external', False):
-            open_url(QUrl(url_slash_cleaner(detail_item if detail_item else url)))
+            open_url(QUrl(url_slash_cleaner(detail_item or url)))
         else:
             d = WebStoreDialog(self.gui, url, parent, detail_item)
             d.setWindowTitle(self.name)

src/calibre/gui2/store/stores/ebookpoint_plugin.py

@@ -54,9 +54,9 @@ class EbookpointStore(BasicStoreConfig, StorePlugin):
             detail_url = aff_root + as_base64(detail_item)
 
         if external or self.config.get('open_external', False):
-            open_url(QUrl(url_slash_cleaner(detail_url if detail_url else aff_url)))
+            open_url(QUrl(url_slash_cleaner(detail_url or aff_url)))
         else:
-            d = WebStoreDialog(self.gui, url, parent, detail_url if detail_url else aff_url)
+            d = WebStoreDialog(self.gui, url, parent, detail_url or aff_url)
             d.setWindowTitle(self.name)
             d.set_tags(self.config.get('tags', ''))
             d.exec()

src/calibre/gui2/store/stores/empik_plugin.py

@@ -53,9 +53,9 @@ class EmpikStore(BasicStoreConfig, StorePlugin):
             detail_url = aff_root + as_base64(detail_item)
 
         if external or self.config.get('open_external', False):
-            open_url(QUrl(url_slash_cleaner(detail_url if detail_url else aff_url)))
+            open_url(QUrl(url_slash_cleaner(detail_url or aff_url)))
         else:
-            d = WebStoreDialog(self.gui, url, parent, detail_url if detail_url else aff_url)
+            d = WebStoreDialog(self.gui, url, parent, detail_url or aff_url)
             d.setWindowTitle(self.name)
             d.set_tags(self.config.get('tags', ''))
             d.exec()

src/calibre/gui2/store/stores/google_books_plugin.py

@@ -84,7 +84,7 @@ class GoogleBooksStore(BasicStoreConfig, StorePlugin):
     def open(self, parent=None, detail_item=None, external=False):
         url = 'https://books.google.com/books'
         if True or external or self.config.get('open_external', False):
-            open_url(QUrl(url_slash_cleaner(detail_item if detail_item else url)))
+            open_url(QUrl(url_slash_cleaner(detail_item or url)))
         else:
             d = WebStoreDialog(self.gui, url, parent, detail_item)
             d.setWindowTitle(self.name)

src/calibre/gui2/store/stores/legimi_plugin.py

@@ -53,9 +53,9 @@ class LegimiStore(BasicStoreConfig, StorePlugin):
             detail_url = aff_root + as_base64(detail_item)
 
         if external or self.config.get('open_external', False):
-            open_url(QUrl(url_slash_cleaner(detail_url if detail_url else aff_url)))
+            open_url(QUrl(url_slash_cleaner(detail_url or aff_url)))
         else:
-            d = WebStoreDialog(self.gui, url, parent, detail_url if detail_url else aff_url)
+            d = WebStoreDialog(self.gui, url, parent, detail_url or aff_url)
             d.setWindowTitle(self.name)
             d.set_tags(self.config.get('tags', ''))
             d.exec()

src/calibre/gui2/store/stores/litres_plugin.py

@@ -45,7 +45,7 @@ class LitResStore(BasicStoreConfig, StorePlugin):
                 u'&art=' + quote(detail_item)
 
         if external or self.config.get('open_external', False):
-            open_url(QUrl(url_slash_cleaner(detail_url if detail_url else url)))
+            open_url(QUrl(url_slash_cleaner(detail_url or url)))
         else:
             d = WebStoreDialog(self.gui, url, parent, detail_url)
             d.setWindowTitle(self.name)

src/calibre/gui2/store/stores/mobileread/cache_progress_dialog.py

@@ -21,7 +21,7 @@ class CacheProgressDialog(QDialog, Ui_Dialog):
 
         self.progress.setValue(0)
         self.progress.setMinimum(0)
-        self.progress.setMaximum(total if total else 0)
+        self.progress.setMaximum(total or 0)
 
     def exec(self):
         self.completed = 0

src/calibre/gui2/store/stores/mobileread/mobileread_plugin.py

@@ -42,7 +42,7 @@ class MobileReadStore(BasicStoreConfig, StorePlugin):
         url = 'https://www.mobileread.com/'
 
         if external or self.config.get('open_external', False):
-            open_url(QUrl(detail_item if detail_item else url))
+            open_url(QUrl(detail_item or url))
         elif detail_item:
             d = WebStoreDialog(self.gui, url, parent, detail_item)
             d.setWindowTitle(self.name)

src/calibre/gui2/store/stores/nexto_plugin.py

@@ -57,9 +57,9 @@ class NextoStore(BasicStoreConfig, StorePlugin):
                 detail_url = aff_root + as_base64('http://www.nexto.pl/rf/pr?p=' + book_id)
 
         if external or self.config.get('open_external', False):
-            open_url(QUrl(url_slash_cleaner(detail_url if detail_url else aff_url)))
+            open_url(QUrl(url_slash_cleaner(detail_url or aff_url)))
         else:
-            d = WebStoreDialog(self.gui, url, parent, detail_url if detail_url else aff_url)
+            d = WebStoreDialog(self.gui, url, parent, detail_url or aff_url)
             d.setWindowTitle(self.name)
             d.set_tags(self.config.get('tags', ''))
             d.exec()

src/calibre/gui2/store/stores/publio_plugin.py

@@ -51,9 +51,9 @@ class PublioStore(BasicStoreConfig, StorePlugin):
             detail_url = aff_root + as_base64(detail_item)
 
         if external or self.config.get('open_external', False):
-            open_url(QUrl(url_slash_cleaner(detail_url if detail_url else aff_url)))
+            open_url(QUrl(url_slash_cleaner(detail_url or aff_url)))
         else:
-            d = WebStoreDialog(self.gui, url, parent, detail_url if detail_url else aff_url)
+            d = WebStoreDialog(self.gui, url, parent, detail_url or aff_url)
             d.setWindowTitle(self.name)
             d.set_tags(self.config.get('tags', ''))
             d.exec()

src/calibre/gui2/store/stores/rw2010_plugin.py

@@ -36,7 +36,7 @@ class RW2010Store(BasicStoreConfig, StorePlugin):
         url = 'http://www.rw2010.pl/'
 
         if external or self.config.get('open_external', False):
-            open_url(QUrl(url_slash_cleaner(detail_item if detail_item else url)))
+            open_url(QUrl(url_slash_cleaner(detail_item or url)))
         else:
             d = WebStoreDialog(self.gui, url, parent, detail_item)
             d.setWindowTitle(self.name)

src/calibre/gui2/store/stores/smashwords_plugin.py

@@ -103,7 +103,7 @@ class SmashwordsStore(BasicStoreConfig, StorePlugin):
         url = url + aff_id
 
         if external or self.config.get('open_external', False):
-            open_url(QUrl(url_slash_cleaner(detail_url if detail_url else url)))
+            open_url(QUrl(url_slash_cleaner(detail_url or url)))
         else:
             d = WebStoreDialog(self.gui, url, parent, detail_url)
             d.setWindowTitle(self.name)

src/calibre/gui2/store/stores/swiatebookow_plugin.py

@@ -53,9 +53,9 @@ class SwiatEbookowStore(BasicStoreConfig, StorePlugin):
             detail_url = aff_root + as_base64(detail_item)
 
         if external or self.config.get('open_external', False):
-            open_url(QUrl(url_slash_cleaner(detail_url if detail_url else aff_url)))
+            open_url(QUrl(url_slash_cleaner(detail_url or aff_url)))
         else:
-            d = WebStoreDialog(self.gui, url, parent, detail_url if detail_url else aff_url)
+            d = WebStoreDialog(self.gui, url, parent, detail_url or aff_url)
             d.setWindowTitle(self.name)
             d.set_tags(self.config.get('tags', ''))
             d.exec()

src/calibre/gui2/store/stores/virtualo_plugin.py

@@ -54,7 +54,7 @@ class VirtualoStore(BasicStoreConfig, StorePlugin):
             detail_url = aff_root + as_base64(detail_item)
 
         if external or self.config.get('open_external', False):
-            open_url(QUrl(url_slash_cleaner(detail_url if detail_url else aff_url)))
+            open_url(QUrl(url_slash_cleaner(detail_url or aff_url)))
         else:
             d = WebStoreDialog(self.gui, url, parent, detail_item)
             d.setWindowTitle(self.name)

src/calibre/gui2/store/stores/weightless_books_plugin.py

@@ -35,7 +35,7 @@ class WeightlessBooksStore(BasicStoreConfig, StorePlugin):
         url = 'http://weightlessbooks.com/'
 
         if external or self.config.get('open_external', False):
-            open_url(QUrl(url_slash_cleaner(detail_item if detail_item else url)))
+            open_url(QUrl(url_slash_cleaner(detail_item or url)))
         else:
             d = WebStoreDialog(self.gui, url, parent, detail_item)
             d.setWindowTitle(self.name)

src/calibre/gui2/store/stores/woblink_plugin.py

@@ -102,9 +102,9 @@ class WoblinkStore(BasicStoreConfig, StorePlugin):
             detail_url = aff_root + as_base64(detail_item)
 
         if external or self.config.get('open_external', False):
-            open_url(QUrl(url_slash_cleaner(detail_url if detail_url else aff_url)))
+            open_url(QUrl(url_slash_cleaner(detail_url or aff_url)))
         else:
-            d = WebStoreDialog(self.gui, url, parent, detail_url if detail_url else aff_url)
+            d = WebStoreDialog(self.gui, url, parent, detail_url or aff_url)
             d.setWindowTitle(self.name)
             d.set_tags(self.config.get('tags', ''))
             d.exec()

src/calibre/gui2/store/stores/wolnelektury_plugin.py

@@ -40,7 +40,7 @@ class WolneLekturyStore(BasicStoreConfig, StorePlugin):
             detail_url = detail_item
 
         if external or self.config.get('open_external', False):
-            open_url(QUrl(url_slash_cleaner(detail_url if detail_url else url)))
+            open_url(QUrl(url_slash_cleaner(detail_url or url)))
         else:
             d = WebStoreDialog(self.gui, url, parent, detail_url)
             d.setWindowTitle(self.name)

src/calibre/gui2/tag_browser/model.py

@@ -84,7 +84,7 @@ class TagTreeItem:  # {{{
             self.tag = Tag(data, category=category_key,
                    is_editable=category_key not in
                             ['news', 'search', 'identifiers', 'languages'],
-                   is_searchable=category_key not in ['search'])
+                   is_searchable=category_key != 'search')
         elif self.type == self.TAG:
             self.tag = data
             self.cached_average_rating = None
@@ -746,7 +746,7 @@ class TagsModel(QAbstractItemModel):  # {{{
                 last_idx = 0
                 for idx,tag in enumerate(data[key]):
                     # Deal with items that don't have sorts, such as formats
-                    t = tag.sort if tag.sort else tag.name
+                    t = tag.sort or tag.name
                     c = icu_upper(t) if t else ' '
                     ordnum, ordlen = collation_order_for_partitioning(c)
                     if last_ordnum != ordnum:

src/calibre/gui2/tag_browser/view.py

@@ -633,7 +633,10 @@ class TagsView(QTreeView):  # {{{
             if has_focus and gprefs['tag_browser_allow_keyboard_focus']:
                 # Reset the focus to the TB. Use the singleshot in case
                 # some of searching is done using queued signals.
-                QTimer.singleShot(0, lambda: self.setFocus())
+                QTimer.singleShot(0, self.set_focus)
+
+    def set_focus(self):
+        self.setFocus()
 
     def conditional_clear(self, search_string):
         if search_string != self.search_string:

src/calibre/gui2/toc/location.py

@@ -56,7 +56,7 @@ class RequestInterceptor(QWebEngineUrlRequestInterceptor):
             request_info.block(True)
             return
         qurl = request_info.requestUrl()
-        if qurl.scheme() not in (FAKE_PROTOCOL,):
+        if qurl.scheme() != FAKE_PROTOCOL:
             default_log.warn(f'Blocking URL request {qurl.toString()} as it is not for a resource in the book')
             request_info.block(True)
             return

src/calibre/gui2/tweak_book/diff/view.py

@@ -1114,7 +1114,7 @@ class DiffView(QWidget):  # {{{
                 d = -1
         elif key in (Qt.Key.Key_PageUp, Qt.Key.Key_PageDown):
             amount = self.scrollbar.pageStep()
-            if key in (Qt.Key.Key_PageUp,):
+            if key == Qt.Key.Key_PageUp:
                 d = -1
         elif key in (Qt.Key.Key_Home, Qt.Key.Key_End):
             self.scrollbar.setValue(0 if key == Qt.Key.Key_Home else self.scrollbar.maximum())

src/calibre/gui2/tweak_book/editor/widget.py

@@ -658,7 +658,7 @@ def launch_editor(path_to_edit, path_is_raw=False, syntax='html', callback=None)
         ext = path_to_edit.rpartition('.')[-1].lower()
         if ext in ('html', 'htm', 'xhtml', 'xhtm'):
             syntax = 'html'
-        elif ext in ('css',):
+        elif ext == 'css':
             syntax = 'css'
     t = Editor(syntax)
     t.data = raw

src/calibre/gui2/tweak_book/search.py

@@ -1245,7 +1245,7 @@ class SavedSearches(QWidget):
             def err():
                 error_dialog(self, _('Invalid data'), _(
                     'The file %s does not contain valid saved searches') % path, show=True)
-            if not isinstance(obj, dict) or 'version' not in obj or 'searches' not in obj or obj['version'] not in (1,):
+            if not isinstance(obj, dict) or 'version' not in obj or 'searches' not in obj or obj['version'] != 1:
                 return err()
             searches = []
             for item in obj['searches']:

src/calibre/gui2/tweak_book/spell.py

@@ -149,7 +149,7 @@ class AddDictionary(QDialog):  # {{{
         def k(dictionary):
             return sort_key(calibre_langcode_to_name(dictionary['primary_locale'].langcode))
 
-        for data in sorted(catalog_online_dictionaries(), key=lambda x:k(x)):
+        for data in sorted(catalog_online_dictionaries(), key=k):
             if languages.get(data['primary_locale'].langcode, {}).get(data['primary_locale'].countrycode, None):
                 continue
             local = calibre_langcode_to_name(data['primary_locale'].langcode)

src/calibre/gui2/widgets.py

@@ -179,7 +179,7 @@ class FilenamePattern(QWidget, Ui_Form):  # {{{
             self.pubdate.setText(_('No match'))
 
         self.isbn.setText(_('No match') if mi.isbn is None else str(mi.isbn))
-        self.comments.setText(mi.comments if mi.comments else _('No match'))
+        self.comments.setText(mi.comments or _('No match'))
 
     def pattern(self):
         pat = str(self.re.lineEdit().text())

src/calibre/gui2/wizard/send_email.py

@@ -323,9 +323,9 @@ class SendEmail(QWidget, Ui_Form):
                 return False
         conf = smtp_prefs()
         conf.set('from_', from_)
-        conf.set('relay_host', host if host else None)
+        conf.set('relay_host', host or None)
         conf.set('relay_port', self.relay_port.value())
-        conf.set('relay_username', username if username else None)
+        conf.set('relay_username', username or None)
         conf.set('relay_password', as_hex_unicode(password))
         conf.set('encryption', enc_method)
         return True

src/calibre/library/catalogs/epub_mobi_builder.py

@@ -942,7 +942,7 @@ class CatalogBuilder:
             if record['publisher']:
                 this_title['publisher'] = record['publisher']
 
-            this_title['rating'] = record['rating'] if record['rating'] else 0
+            this_title['rating'] = record['rating'] or 0
 
             if is_date_undefined(record['pubdate']):
                 this_title['date'] = None

src/calibre/library/custom_columns.py

@@ -230,7 +230,7 @@ class CustomColumns:
         if num is not None:
             data = self.custom_column_num_map[num]
         # add future datatypes with an extra column here
-        if data['datatype'] not in ['series']:
+        if data['datatype'] != 'series':
             return None
         ign,lt = self.custom_table_names(data['num'])
         idx = idx if index_is_id else self.id(idx)
@@ -689,7 +689,7 @@ class CustomColumns:
             dt = 'INT'
         elif datatype in ('text', 'comments', 'series', 'composite', 'enumeration'):
             dt = 'TEXT'
-        elif datatype in ('float',):
+        elif datatype == 'float':
             dt = 'REAL'
         elif datatype == 'datetime':
             dt = 'timestamp'

src/calibre/library/database.py

@@ -1296,7 +1296,7 @@ ALTER TABLE books ADD COLUMN isbn TEXT DEFAULT "" COLLATE NOCASE;
         rating = int(rating)
         self.conn.execute('DELETE FROM books_ratings_link WHERE book=?',(id,))
         rat = self.conn.get('SELECT id FROM ratings WHERE rating=?', (rating,), all=False)
-        rat = rat if rat else self.conn.execute('INSERT INTO ratings(rating) VALUES (?)', (rating,)).lastrowid
+        rat = rat or self.conn.execute('INSERT INTO ratings(rating) VALUES (?)', (rating,)).lastrowid
         self.conn.execute('INSERT INTO books_ratings_link(book, rating) VALUES (?,?)', (id, rat))
         self.conn.commit()
 
@@ -1350,7 +1350,7 @@ ALTER TABLE books ADD COLUMN isbn TEXT DEFAULT "" COLLATE NOCASE;
                 duplicates.append((path, format, mi, uri))
                 continue
             series_index = 1 if mi.series_index is None else mi.series_index
-            aus = mi.author_sort if mi.author_sort else ', '.join(mi.authors)
+            aus = mi.author_sort or ', '.join(mi.authors)
             obj = self.conn.execute('INSERT INTO books(title, uri, series_index, author_sort) VALUES (?, ?, ?, ?)',
                               (mi.title, uri, series_index, aus))
             id = obj.lastrowid
@@ -1493,7 +1493,7 @@ class SearchToken:
             if not text:
                 text = ''
         else:
-            text = ' '.join([item[i] if item[i] else '' for i in self.FIELD_MAP.values()])
+            text = ' '.join([item[i] or '' for i in self.FIELD_MAP.values()])
         return bool(self.pattern.search(text)) ^ self.negate
 
 

src/calibre/library/database2.py

@@ -204,7 +204,7 @@ class LibraryDatabase2(LibraryDatabase, SchemaUpgrade, CustomColumns):
             progress_callback(None, len(default_prefs))
             for i, key in enumerate(default_prefs):
                 # be sure that prefs not to be copied are listed below
-                if not restore_all_prefs and key in frozenset(['news_to_be_synced']):
+                if not restore_all_prefs and key == 'news_to_be_synced':
                     continue
                 dbprefs[key] = default_prefs[key]
                 progress_callback(_('restored preference ') + key, i+1)
@@ -3465,7 +3465,7 @@ class LibraryDatabase2(LibraryDatabase, SchemaUpgrade, CustomColumns):
             return None
         series_index = self.get_next_series_num_for(mi.series) \
                     if mi.series_index is None else mi.series_index
-        aus = mi.author_sort if mi.author_sort else self.author_sort_from_authors(mi.authors)
+        aus = mi.author_sort or self.author_sort_from_authors(mi.authors)
         title = mi.title
         if isbytestring(aus):
             aus = aus.decode(preferred_encoding, 'replace')
@@ -3513,7 +3513,7 @@ class LibraryDatabase2(LibraryDatabase, SchemaUpgrade, CustomColumns):
                 continue
             series_index = self.get_next_series_num_for(mi.series) \
                             if mi.series_index is None else mi.series_index
-            aus = mi.author_sort if mi.author_sort else self.author_sort_from_authors(mi.authors)
+            aus = mi.author_sort or self.author_sort_from_authors(mi.authors)
             title = mi.title
             if isinstance(aus, bytes):
                 aus = aus.decode(preferred_encoding, 'replace')
@@ -3556,7 +3556,7 @@ class LibraryDatabase2(LibraryDatabase, SchemaUpgrade, CustomColumns):
             mi.title = _('Unknown')
         if not mi.authors:
             mi.authors = [_('Unknown')]
-        aus = mi.author_sort if mi.author_sort else self.author_sort_from_authors(mi.authors)
+        aus = mi.author_sort or self.author_sort_from_authors(mi.authors)
         if isinstance(aus, bytes):
             aus = aus.decode(preferred_encoding, 'replace')
         title = mi.title if isinstance(mi.title, str) else \

src/calibre/srv/legacy.py

@@ -69,7 +69,7 @@ def build_search_box(num, search, sort, order, ctx, field_metadata, library_id):
     num_select.tail = ' books matching '
     form.append(num_select)
 
-    searchf = E.input(name='search', id='s', value=search if search else '')
+    searchf = E.input(name='search', id='s', value=search or '')
     searchf.tail = _(' sorted by ')
     form.append(searchf)
 

src/calibre/utils/forked_map.py

@@ -10,10 +10,7 @@ import traceback
 from collections.abc import Callable, Iterator
 from contextlib import ExitStack
 from itertools import chain, islice
-from typing import Any, BinaryIO, NamedTuple, TypeVar
-
-T = TypeVar('T')
-R = TypeVar('R')
+from typing import Any, BinaryIO, NamedTuple
 
 try:
     from itertools import batched
@@ -111,7 +108,7 @@ def run_jobs(*jobs: Job) -> Worker:
         os._exit(os.EX_OK)
 
 
-def forked_map(fn: Callable[[T], R], iterable: T, *iterables: T, timeout: int | float | None = None, num_workers: int = 0) -> Iterator[R]:
+def forked_map[T, R](fn: Callable[[T], R], iterable: T, *iterables: T, timeout: int | float | None = None, num_workers: int = 0) -> Iterator[R]:
     '''
     Should be used only in worker processes that have no threads and that do not use/import any non fork safe libraries such as macOS
     system libraries.