Use f-strings where possible

sphinx/application.py

@@ -1292,7 +1292,8 @@ def is_parallel_allowed(self, typ: str) -> bool:
                                       "to check and make it explicit")
             message_not_safe = __("the %s extension is not safe for parallel writing")
         else:
-            raise ValueError('parallel type %s is not supported' % typ)
+            msg = f'parallel type {typ} is not supported'
+            raise ValueError(msg)
 
         for ext in self.extensions.values():
             allowed = getattr(ext, attrname, None)
@@ -1316,7 +1317,8 @@ def set_html_assets_policy(self, policy: Literal['always', 'per_page']) -> None:
         .. versionadded: 4.1
         """
         if policy not in ('always', 'per_page'):
-            raise ValueError('policy %s is not supported' % policy)
+            msg = f'policy {policy} is not supported'
+            raise ValueError(msg)
         self.registry.html_assets_policy = policy
 
 

sphinx/builders/__init__.py

@@ -92,8 +92,8 @@ def __init__(self, app: Sphinx, env: BuildEnvironment) -> None:
         self.tags: Tags = app.tags
         self.tags.add(self.format)
         self.tags.add(self.name)
-        self.tags.add("format_%s" % self.format)
-        self.tags.add("builder_%s" % self.name)
+        self.tags.add(f'format_{self.format}')
+        self.tags.add(f'builder_{self.name}')
 
         # images that need to be copied over (source -> dest)
         self.images: dict[str, str] = {}
@@ -419,8 +419,8 @@ def read(self) -> list[str]:
             self._read_serial(docnames)
 
         if self.config.root_doc not in self.env.all_docs:
-            raise SphinxError('root file %s not found' %
-                              self.env.doc2path(self.config.root_doc))
+            msg = f'root file {self.env.doc2path(self.config.root_doc)} not found'
+            raise SphinxError(msg)
 
         for retval in self.events.emit('env-updated', self.env):
             if retval is not None:

sphinx/builders/changes.py

@@ -106,17 +106,18 @@ def write(self, *ignored: Any) -> None:
         with open(path.join(self.outdir, 'changes.html'), 'w', encoding='utf8') as f:
             f.write(self.templates.render('changes/versionchanges.html', ctx))
 
-        hltext = ['.. versionadded:: %s' % version,
-                  '.. versionchanged:: %s' % version,
-                  '.. deprecated:: %s' % version,
-                  '.. versionremoved:: %s' % version,
-                  ]
+        hltext = [
+            f'.. versionadded:: {version}',
+            f'.. versionchanged:: {version}',
+            f'.. deprecated:: {version}',
+            f'.. versionremoved:: {version}',
+        ]
 
         def hl(no: int, line: str) -> str:
-            line = '<a name="L%s"> </a>' % no + html.escape(line)
+            line = f'<a name="L{no}"> </a>{html.escape(line)}'
             for x in hltext:
                 if x in line:
-                    line = '<span class="hl">%s</span>' % line
+                    line = f'<span class="hl">{line}</span>'
                     break
             return line
 

sphinx/builders/html/__init__.py

@@ -153,9 +153,8 @@ def dump(self, f: IO) -> None:
         f.write('# Sphinx build info version 1\n'
                 '# This file hashes the configuration used when building these files.'
                 ' When it is not found, a full rebuild will be done.\n'
-                'config: %s\n'
-                'tags: %s\n' %
-                (self.config_hash, self.tags_hash))
+                f'config: {self.config_hash}\n'
+                f'tags: {self.tags_hash}\n')
 
 
 class StandaloneHTMLBuilder(Builder):

sphinx/builders/latex/transforms.py

@@ -102,7 +102,7 @@ def expand_show_urls(self) -> None:
 
                         self.expanded = True
                     else:  # all other true values (b/w compat)
-                        textnode = nodes.Text(" (%s)" % uri)
+                        textnode = nodes.Text(f' ({uri})')
                         node.parent.insert(index + 1, textnode)
 
     def get_docname_for_node(self, node: Node) -> str:

sphinx/builders/linkcheck.py

@@ -162,7 +162,8 @@ def process_result(self, result: CheckResult) -> None:
             self.write_entry('redirected ' + text, result.docname, filename,
                              result.lineno, result.uri + ' to ' + result.message)
         else:
-            raise ValueError('Unknown status %s.' % result.status)
+            msg = f'Unknown status {result.status}.'
+            raise ValueError(msg)
 
     def write_linkstat(self, data: dict) -> None:
         self.json_outfile.write(json.dumps(data))

sphinx/builders/manpage.py

@@ -80,7 +80,7 @@ def write(self, *ignored: Any) -> None:
             docsettings.section = section
 
             if self.config.man_make_section_directory:
-                dirname = 'man%s' % section
+                dirname = f'man{section}'
                 ensuredir(path.join(self.outdir, dirname))
                 targetname = f'{dirname}/{name}.{section}'
             else:

sphinx/cmd/build.py

@@ -63,7 +63,7 @@ def handle_exception(
             print(red(__('reST markup error:')), file=stderr)
             print(terminal_safe(exception.args[0]), file=stderr)
         elif isinstance(exception, SphinxError):
-            print(red('%s:' % exception.category), file=stderr)
+            print(red(f'{exception.category}:'), file=stderr)
             print(str(exception), file=stderr)
         elif isinstance(exception, UnicodeError):
             print(red(__('Encoding error:')), file=stderr)

sphinx/cmd/make_mode.py

@@ -72,15 +72,15 @@ def build_clean(self) -> int:
         if not path.exists(self.builddir):
             return 0
         elif not path.isdir(self.builddir):
-            print("Error: %r is not a directory!" % self.builddir)
+            print(f'Error: {self.builddir!r} is not a directory!')
             return 1
         elif srcdir == builddir:
-            print("Error: %r is same as source directory!" % self.builddir)
+            print(f'Error: {self.builddir!r} is same as source directory!')
             return 1
         elif path.commonpath([srcdir, builddir]) == builddir:
-            print("Error: %r directory contains source directory!" % self.builddir)
+            print(f'Error: {self.builddir!r} directory contains source directory!')
             return 1
-        print("Removing everything under %r..." % self.builddir)
+        print(f'Removing everything under {self.builddir!r}...')
         for item in os.listdir(self.builddir):
             rmtree(self.builddir_join(item))
         return 0
@@ -89,8 +89,9 @@ def build_help(self) -> None:
         if not color_terminal():
             nocolor()
 
-        print(bold("Sphinx v%s" % sphinx.__display_version__))
-        print("Please use `make %s' where %s is one of" % ((blue('target'),) * 2))
+        target = blue('target')
+        print(bold(f'Sphinx v{sphinx.__display_version__}'))
+        print(f"Please use `make {target}' where {target} is one of")
         for osname, bname, description in BUILDERS:
             if not osname or os.name == osname:
                 print(f'  {blue(bname.ljust(10))}  {description}')
@@ -103,12 +104,13 @@ def build_latexpdf(self) -> int:
         make_fallback = 'make.bat' if sys.platform == 'win32' else 'make'
         makecmd = os.environ.get('MAKE', make_fallback)
         if not makecmd.lower().startswith('make'):
-            raise RuntimeError('Invalid $MAKE command: %r' % makecmd)
+            msg = f'Invalid $MAKE command: {makecmd!r}'
+            raise RuntimeError(msg)
         try:
             with chdir(self.builddir_join('latex')):
                 return subprocess.call([makecmd, 'all-pdf'])
         except OSError:
-            print('Error: Failed to run: %s' % makecmd)
+            print(f'Error: Failed to run: {makecmd}')
             return 1
 
     def build_latexpdfja(self) -> int:
@@ -119,12 +121,13 @@ def build_latexpdfja(self) -> int:
         make_fallback = 'make.bat' if sys.platform == 'win32' else 'make'
         makecmd = os.environ.get('MAKE', make_fallback)
         if not makecmd.lower().startswith('make'):
-            raise RuntimeError('Invalid $MAKE command: %r' % makecmd)
+            msg = f'Invalid $MAKE command: {makecmd!r}'
+            raise RuntimeError(msg)
         try:
             with chdir(self.builddir_join('latex')):
                 return subprocess.call([makecmd, 'all-pdf'])
         except OSError:
-            print('Error: Failed to run: %s' % makecmd)
+            print(f'Error: Failed to run: {makecmd}')
             return 1
 
     def build_info(self) -> int:
@@ -134,12 +137,13 @@ def build_info(self) -> int:
         # Use $MAKE to determine the make command
         makecmd = os.environ.get('MAKE', 'make')
         if not makecmd.lower().startswith('make'):
-            raise RuntimeError('Invalid $MAKE command: %r' % makecmd)
+            msg = f'Invalid $MAKE command: {makecmd!r}'
+            raise RuntimeError(msg)
         try:
             with chdir(self.builddir_join('texinfo')):
                 return subprocess.call([makecmd, 'info'])
         except OSError:
-            print('Error: Failed to run: %s' % makecmd)
+            print(f'Error: Failed to run: {makecmd}')
             return 1
 
     def build_gettext(self) -> int:

sphinx/cmd/quickstart.py

@@ -478,7 +478,7 @@ def get_parser() -> argparse.ArgumentParser:
                         default=None,
                         help=__('quiet mode'))
     parser.add_argument('--version', action='version', dest='show_version',
-                        version='%%(prog)s %s' % __display_version__)
+                        version=f'%(prog)s {__display_version__}')
 
     parser.add_argument('path', metavar='PROJECT_DIR', default='.', nargs='?',
                         help=__('project root'))
@@ -511,8 +511,8 @@ def get_parser() -> argparse.ArgumentParser:
 
     group = parser.add_argument_group(__('Extension options'))
     for ext in EXTENSIONS:
-        group.add_argument('--ext-%s' % ext, action='append_const',
-                           const='sphinx.ext.%s' % ext, dest='extensions',
+        group.add_argument(f'--ext-{ext}', action='append_const',
+                           const=f'sphinx.ext.{ext}', dest='extensions',
                            help=__('enable %s extension') % ext)
     group.add_argument('--extensions', metavar='EXTENSIONS', dest='extensions',
                        action='append', help=__('enable arbitrary extensions'))

sphinx/directives/__init__.py

@@ -326,7 +326,7 @@ def run(self) -> list[Node]:
         else:
             literal_block = nodes.literal_block(self.block_text, self.block_text)
             reporter = self.state.reporter
-            error = reporter.error('Unknown interpreted text role "%s".' % role_name,
+            error = reporter.error(f'Unknown interpreted text role "{role_name}".',
                                    literal_block, line=self.lineno)
             messages += [error]
 

sphinx/directives/code.py

@@ -320,9 +320,11 @@ def start_filter(
                         return lines[lineno:]
 
             if inclusive is True:
-                raise ValueError('start-after pattern not found: %s' % start)
+                msg = f'start-after pattern not found: {start}'
+                raise ValueError(msg)
             else:
-                raise ValueError('start-at pattern not found: %s' % start)
+                msg = f'start-at pattern not found: {start}'
+                raise ValueError(msg)
 
         return lines
 
@@ -349,9 +351,11 @@ def end_filter(
                         else:
                             return lines[:lineno]
             if inclusive is True:
-                raise ValueError('end-at pattern not found: %s' % end)
+                msg = f'end-at pattern not found: {end}'
+                raise ValueError(msg)
             else:
-                raise ValueError('end-before pattern not found: %s' % end)
+                msg = f'end-before pattern not found: {end}'
+                raise ValueError(msg)
 
         return lines
 

sphinx/directives/patches.py

@@ -158,7 +158,7 @@ def add_target(self, ret: list[Node]) -> None:
         # assign label automatically if math_number_all enabled
         if node['label'] == '' or (self.config.math_number_all and not node['label']):
             seq = self.env.new_serialno('sphinx.ext.math#equations')
-            node['label'] = "%s:%d" % (self.env.docname, seq)
+            node['label'] = f'{self.env.docname}:{seq}'
 
         # no targets and numbers are needed
         if not node['label']:
@@ -170,7 +170,7 @@ def add_target(self, ret: list[Node]) -> None:
         node['number'] = domain.get_equation_number_for(node['label'])
 
         # add target node
-        node_id = make_id('equation-%s' % node['label'])
+        node_id = make_id(f'equation-{node["label"]}')
         target = nodes.target('', '', ids=[node_id])
         self.state.document.note_explicit_target(target)
         ret.insert(0, target)

sphinx/domains/__init__.py

@@ -94,8 +94,8 @@ class Index(ABC):
 
     def __init__(self, domain: Domain) -> None:
         if not self.name or self.localname is None:
-            raise SphinxError('Index subclass %s has no valid name or localname'
-                              % self.__class__.__name__)
+            msg = f'Index subclass {self.__class__.__name__} has no valid name or localname'
+            raise SphinxError(msg)
         self.domain = domain
 
     @abstractmethod
@@ -223,7 +223,8 @@ def __init__(self, env: BuildEnvironment) -> None:
         else:
             self.data = env.domaindata[self.name]
             if self.data['version'] != self.data_version:
-                raise OSError('data of %r domain out of date' % self.label)
+                msg = f'data of {self.label!r} domain out of date'
+                raise OSError(msg)
         for name, obj in self.object_types.items():
             for rolename in obj.roles:
                 self._role2type.setdefault(rolename, []).append(name)
@@ -300,9 +301,11 @@ def merge_domaindata(self, docnames: list[str], otherdata: dict[str, Any]) -> No
         """Merge in data regarding *docnames* from a different domaindata
         inventory (coming from a subprocess in parallel builds).
         """
-        raise NotImplementedError('merge_domaindata must be implemented in %s '
-                                  'to be able to do parallel builds!' %
-                                  self.__class__)
+        msg = (
+            f'merge_domaindata must be implemented in {self.__class__} '
+            'to be able to do parallel builds!'
+        )
+        raise NotImplementedError(msg)
 
     def process_doc(self, env: BuildEnvironment, docname: str,
                     document: nodes.document) -> None:

sphinx/domains/c/__init__.py

@@ -259,8 +259,10 @@ def handle_signature(self, sig: str, signode: TextElement) -> ASTDeclaration:
             self.env.temp_data['c:last_symbol'] = e.symbol
             msg = __("Duplicate C declaration, also defined at %s:%s.\n"
                      "Declaration is '.. c:%s:: %s'.")
-            msg = msg % (e.symbol.docname, e.symbol.line, self.display_object_type, sig)
-            logger.warning(msg, location=signode)
+            logger.warning(msg,
+                           e.symbol.docname, e.symbol.line,
+                           self.display_object_type, sig,
+                           location=signode)
 
         if ast.objectType == 'enumerator':
             self._add_enumerator_to_parent(ast)

sphinx/domains/c/_ast.py

@@ -88,7 +88,8 @@ def describe_signature(self, signode: TextElement, mode: str, env: BuildEnvironm
         elif mode == 'noneIsName':
             signode += node
         else:
-            raise Exception('Unknown description mode: %s' % mode)
+            msg = f'Unknown description mode: {mode}'
+            raise Exception(msg)
 
     @property
     def identifier(self) -> str:
@@ -183,7 +184,8 @@ def describe_signature(self, signode: TextElement, mode: str,
                     signode += dest
                 self.names[-1].describe_signature(signode, mode, env, '', symbol)
         else:
-            raise Exception('Unknown description mode: %s' % mode)
+            msg = f'Unknown description mode: {mode}'
+            raise Exception(msg)
 
 
 ################################################################################
@@ -1365,8 +1367,8 @@ def __hash__(self) -> int:
         return hash(self.exprs)
 
     def _stringify(self, transform: StringifyTransform) -> str:
-        exprs = [transform(e) for e in self.exprs]
-        return '(%s)' % ', '.join(exprs)
+        exprs = ', '.join(map(transform, self.exprs))
+        return f'({exprs})'
 
     def describe_signature(self, signode: TextElement, mode: str,
                            env: BuildEnvironment, symbol: Symbol) -> None: