write better list/set/dict comprehensions (extra-edit)

manual/custom.py

@@ -198,7 +198,7 @@ details and examples.
         lines += [f'.. _calibredb-{language}-{cmd}:', '']
         lines += [cmd, '~'*20, '']
         usage = parser.usage.strip()
-        usage = list(usage.replace('%prog', 'calibredb').splitlines())
+        usage = 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/1843.recipe

@@ -262,7 +262,7 @@ class Economist(BasicNewsRecipe):
                     url = 'file:///' + pt.name
                     feeds_dict[section].append({'title': title, 'url': url, 'description': desc})
                     self.log('\t', title, '\n\t\t', desc)
-            return [(section, articles) for section, articles in feeds_dict.items()]
+            return list(feeds_dict.items())
 
         def populate_article_metadata(self, article, soup, first):
             article.url = soup.find('h1')['title']

recipes/andhrajyothy_ap.recipe

@@ -76,7 +76,7 @@ class andhra(BasicNewsRecipe):
                 if snaps['ObjectType'] == 4:
                     continue
                 feeds_dict[section].append({'title': '', 'url': url})
-        return [(section, articles) for section, articles in feeds_dict.items()]
+        return list(feeds_dict.items())
 
     def preprocess_raw_html(self, raw, *a):
         data = json.loads(raw)

recipes/andhrajyothy_tel.recipe

@@ -76,7 +76,7 @@ class andhra(BasicNewsRecipe):
                 if snaps['ObjectType'] == 4:
                     continue
                 feeds_dict[section].append({'title': '', 'url': url})
-        return [(section, articles) for section, articles in feeds_dict.items()]
+        return list(feeds_dict.items())
 
     def preprocess_raw_html(self, raw, *a):
         data = json.loads(raw)

recipes/barrons.recipe

@@ -127,7 +127,7 @@ class barrons(BasicNewsRecipe):
                 desc += ' | ' + self.tag_to_string(summ)
             self.log('\t', title, ' ', url, '\n\t', desc)
             ans[section].append({'title': title, 'url': url, 'description': desc})
-        return [(section, articles) for section, articles in ans.items()]
+        return list(ans.items())
 
     def print_version(self, url):
         return url.split('?')[0].replace('/articles/', '/amp/articles/')

recipes/boston_globe_print_edition.recipe

@@ -95,7 +95,7 @@ class BostonGlobePrint(BasicNewsRecipe):
 
                 self.log(section, '\n\t', title, '\n\t', desc, '\n\t\t', url)
                 feeds_dict[section].append({'title': title, 'url': url, 'description': desc})
-        return [(section, articles) for section, articles in feeds_dict.items()]
+        return list(feeds_dict.items())
 
     def preprocess_raw_html(self, raw_html, url):
         soup = self.index_to_soup(raw_html)

recipes/chronicle_higher_ed.recipe

@@ -77,7 +77,7 @@ class Chronicle(BasicNewsRecipe):
                     if section_title not in feeds:
                         feeds[section_title] = []
                     feeds[section_title] += articles
-        ans = [(key, val) for key, val in feeds.items()]
+        ans = list(feeds.items())
         return ans
 
     def preprocess_html(self, soup):

recipes/economist.recipe

@@ -382,7 +382,7 @@ class Economist(BasicNewsRecipe):
             url = 'file:///' + pt.name
             feeds_dict[section].append({'title': title, 'url': url, 'description': desc})
             self.log('\t', title, '\n\t\t', desc)
-        return [(section, articles) for section, articles in feeds_dict.items()]
+        return list(feeds_dict.items())
 
     def populate_article_metadata(self, article, soup, first):
         if not self.from_archive:

recipes/economist_free.recipe

@@ -382,7 +382,7 @@ class Economist(BasicNewsRecipe):
             url = 'file:///' + pt.name
             feeds_dict[section].append({'title': title, 'url': url, 'description': desc})
             self.log('\t', title, '\n\t\t', desc)
-        return [(section, articles) for section, articles in feeds_dict.items()]
+        return list(feeds_dict.items())
 
     def populate_article_metadata(self, article, soup, first):
         if not self.from_archive:

recipes/epw_magazine.recipe

@@ -72,5 +72,5 @@ class epw(BasicNewsRecipe):
                 if section_title not in feeds:
                     feeds[section_title] = []
                 feeds[section_title] += articles
-        ans = [(key, val) for key, val in feeds.items()]
+        ans = list(feeds.items())
         return ans

recipes/fokus.recipe

@@ -276,7 +276,7 @@ class Fokus(BasicNewsRecipe):
         section_to_articles = self.assign_articles_to_sections(sections, articles)
 
         # Convert to the expected `list[tuple[str, dict[str, str, str, str]]]` format.
-        feeds = [(section_url, article_dicts) for section_url, article_dicts in section_to_articles.items()]
+        feeds = list(section_to_articles.items())
         num_articles = sum(len(article_dicts) for article_dicts in section_to_articles.values())
         self.log(f'A total of {num_articles} articles belonging to {len(section_to_articles)} sections were kept.')
 

recipes/foreign_policy.recipe

@@ -86,7 +86,7 @@ class ForeignPolicy(BasicNewsRecipe):
                     desc += ' | ' + self.tag_to_string(dek)
                 self.log('\t', title, url, '\n\t', desc)
                 feeds_dict[current_section].append({'title': title, 'url': url, 'description': desc})
-        return [(section, articles) for section, articles in feeds_dict.items()]
+        return list(feeds_dict.items())
 
     def preprocess_html(self, soup):
         for img in soup.findAll('img', attrs={'src':True}):

recipes/frontline.recipe

@@ -96,4 +96,4 @@ class Frontline(BasicNewsRecipe):
                 continue
             self.log(section, '\n\t', title, '\n\t', desc, '\n\t\t', url)
             feeds_dict[section].append({'title': title, 'url': url, 'description': desc})
-        return [(section, articles) for section, articles in feeds_dict.items()]
+        return list(feeds_dict.items())

recipes/hindu.recipe

@@ -134,6 +134,6 @@ class TheHindu(BasicNewsRecipe):
                         desc = 'Page no.' + item['pageno'] + ' | ' + item['teaser_text'] or ''
                         self.log('            ', title, '\n\t', url)
                         feeds_dict[section].append({'title': title, 'url': url, 'description': desc})
-                return [(section, articles) for section, articles in feeds_dict.items()]
+                return list(feeds_dict.items())
             else:
                 return []

recipes/hindustan_times_print.recipe

@@ -98,7 +98,7 @@ class ht(BasicNewsRecipe):
                 desc = page_no
                 self.log('\t', title, ' ', desc)
                 feeds_dict[section].append({'title': title, 'description': desc, 'url': url})
-        return [(section, articles) for section, articles in feeds_dict.items()]
+        return list(feeds_dict.items())
 
 
     def preprocess_raw_html(self, raw, *a):

recipes/history_today.recipe

@@ -85,7 +85,7 @@ class HistoryToday(BasicNewsRecipe):
                         feeds[section_title] = []
                     feeds[section_title] += articles
 
-        ans = [(key, val) for key, val in feeds.items()]
+        ans = list(feeds.items())
         return ans
 
     def cleanup(self):

recipes/mit_technology_review.recipe

@@ -151,7 +151,7 @@ class MitTechnologyReview(BasicNewsRecipe):
                 if section_title not in feeds:
                     feeds[section_title] = []
                 feeds[section_title] += articles
-        ans = [(key, val) for key, val in feeds.items()]
+        ans = list(feeds.items())
         return ans
 
     def preprocess_html(self, soup):

recipes/phillosophy_now.recipe

@@ -82,7 +82,7 @@ class PhilosophyNow(BasicNewsRecipe):
                 if section_title not in feeds:
                     feeds[section_title] = []
                 feeds[section_title] += articles
-        ans = [(key, val) for key, val in feeds.items()]
+        ans = list(feeds.items())
         return ans
 
     # PN changes the content it delivers based on cookies, so the

recipes/sportstar.recipe

@@ -85,7 +85,7 @@ class Sportstar(BasicNewsRecipe):
                 if section_title not in feeds:
                     feeds[section_title] = []
                 feeds[section_title] += articles
-        ans = [(key, val) for key, val in feeds.items()]
+        ans = list(feeds.items())
         return ans
 
     def preprocess_html(self, soup):

recipes/strange_horizons.recipe

@@ -65,4 +65,4 @@ class StrangeHorizons(BasicNewsRecipe):
 
             self.log(sec, '\n\t', title, '\n\t', desc, '\n\t\t', url)
             feeds_dict[sec].append({'title': title, 'url': url, 'description': desc})
-        return [(section, articles) for section, articles in feeds_dict.items()]
+        return list(feeds_dict.items())

src/calibre/db/legacy.py

@@ -287,7 +287,7 @@ class LibraryDatabase:
         return [[k, v] for k, v in iteritems(self.new_api.get_usage_count_by_id(field))]
 
     def field_id_map(self, field):
-        return [(k, v) for k, v in iteritems(self.new_api.get_id_map(field))]
+        return list(iteritems(self.new_api.get_id_map(field)))
 
     def get_custom_items_with_ids(self, label=None, num=None):
         try:

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

@@ -1395,8 +1395,7 @@ class Amazon(Source):
                 q['field-keywords'] += ' ' + q.pop(f, '')
             q['field-keywords'] = q['field-keywords'].strip()
 
-        encoded_q = {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/oeb/iterator/book.py

@@ -106,7 +106,7 @@ class EbookIterator(BookmarksMixin):
 
     def search(self, text, index, backwards=False):
         from calibre.ebooks.oeb.polish.parsing import parse
-        pmap = [(i, path) for i, path in enumerate(self.spine)]
+        pmap = list(enumerate(self.spine))
         if backwards:
             pmap.reverse()
         q = text.lower()

src/calibre/ebooks/pdf/reflow.py

@@ -644,8 +644,7 @@ class Region:
     def collect_stats(self):
         for column in self.columns:
             column.collect_stats()
-        self.average_line_separation = sum([x.average_line_separation for x in
+        self.average_line_separation = sum(x.average_line_separation for x in self.columns)/float(len(self.columns))
-            self.columns])/float(len(self.columns))
 
     def __iter__(self):
         yield from self.columns
@@ -1263,8 +1262,7 @@ class Page:
                         absorb_into = prev_region
                         if self.regions[next_region].line_count >= \
                                 self.regions[prev_region].line_count:
-                            avg_column_count = sum([len(r.columns) for r in
+                            avg_column_count = sum(len(r.columns) for r in regions)/float(len(regions))
-                                regions])/float(len(regions))
                             if self.regions[next_region].line_count > \
                                     self.regions[prev_region].line_count \
                                or abs(avg_column_count -

src/calibre/gui2/custom_column_widgets.py

@@ -887,7 +887,7 @@ def get_field_list(db, use_defaults=False, pref_data_override=None):
         for k in fields:
             if k not in result:
                 result[k] = True
-        return [(k,v) for k,v in result.items()]
+        return list(result.items())
 
 
 def get_custom_columns_to_display_in_editor(db):

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 = list(key.split('.'))
+                path_parts = key.split('.')
                 path = ''
                 last_category_node = self.root_item
                 tree_root = self.user_category_node_tree

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 = [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(list(sorted(available_presets.keys())))))
+                    print(_('Stored presets: {}').format(', '.join(sorted(available_presets.keys()))))
                 else:
                     print(_('Error: No stored presets.'))
                 return 1

src/calibre/spell/dictionary.py

@@ -37,11 +37,10 @@ class UserDictionary:
     def __init__(self, **kwargs):
         self.name = kwargs['name']
         self.is_active = kwargs['is_active']
-        self.words = {(w, langcode) for w, langcode in kwargs['words']}
+        self.words = set(kwargs['words'])
 
     def serialize(self):
-        return {'name':self.name, 'is_active': self.is_active, 'words':[
+        return {'name':self.name, 'is_active': self.is_active, 'words': list(self.words)}
-            (w, l) for w, l in self.words]}
 
 
 _builtins = _custom = None

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(list(item)))
+        return self.utf8ToBibtex(' and '.join(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 = list(chars.split(','))
+    chars = chars.split(',')
     individual, ranges = set(), set()
 
     def not_single(c):