Using f-strings where possible.

docs/conf.py

@@ -283,10 +283,10 @@ def __getattr__(cls, name: str) -> 'Mock':
 os.makedirs('stories', exist_ok=True)
 os.makedirs('spec', exist_ok=True)
 for area in areas:
-    with open('{}.rst'.format(area.lstrip('/')), 'w') as doc:
+    with open(f"{area.lstrip('/')}.rst", 'w') as doc:
         # Anchor and title
         doc.write(f'.. _{area}:\n\n')
-        doc.write('{}\n{}\n'.format(areas[area], '=' * len(areas[area])))
+        doc.write(f"{areas[area]}\n{'=' * len(areas[area])}\n")
         # Included stories
         for story in tree.stories(names=[area], whole=True):
             if story.enabled:

tmt/base.py

@@ -3010,7 +3010,7 @@ def go(self) -> None:
         # Show summary, store run data
         if not self.plans:
             raise tmt.utils.GeneralError("No plans found.")
-        self.verbose('Found {}.'.format(listed(self.plans, 'plan')))
+        self.verbose(f"Found {listed(self.plans, 'plan')}.")
         self.save()
 
         # Iterate over plans

tmt/cli.py

@@ -120,8 +120,7 @@ def get_command(  # type: ignore[override]
             return None
         if len(matches) == 1:
             return click.Group.get_command(self, context, matches[0])
-        context.fail('Did you mean {}?'.format(
-            listed(sorted(matches), join='or')))
+        context.fail(f"Did you mean {listed(sorted(matches), join='or')}?")
         return None
 
 
@@ -1209,7 +1208,7 @@ def headfoot(text: str) -> None:
         headfoot(f'{round(100 * test_coverage / total)}%')
     if docs:
         headfoot(f'{round(100 * docs_coverage / total)}%')
-    headfoot('from {}'.format(listed(total, 'story')))
+    headfoot(f"from {listed(total, 'story')}")
     echo()
 
 
@@ -1354,8 +1353,7 @@ def stories_id(
 @option(
     '-t', '--template', default='empty', metavar='TEMPLATE',
     type=click.Choice(['empty', *tmt.templates.INIT_TEMPLATES]),
-    help='Template ({}).'.format(
-        listed(tmt.templates.INIT_TEMPLATES, join='or')))
+    help=f"Template ({listed(tmt.templates.INIT_TEMPLATES, join='or')}).")
 @verbosity_options
 @force_dry_options
 def init(

tmt/convert.py

@@ -455,8 +455,7 @@ def read(
             with open(datafile_path, encoding='utf-8') as datafile_file:
                 datafile = datafile_file.read()
         except OSError:
-            raise ConvertError("Unable to open '{}'.".format(
-                datafile_path))
+            raise ConvertError(f"Unable to open '{datafile_path}'.")
         echo(f"found in '{datafile_path}'.")
 
     # If testinfo.desc exists read it to preserve content and remove it
@@ -489,8 +488,7 @@ def read(
                 stdout=subprocess.DEVNULL)
         except FileNotFoundError:
             raise ConvertError(
-                "Install tmt-test-convert to "
-                "convert metadata from {}.".format(filename))
+                f"Install tmt-test-convert to convert metadata from {filename}.")
         except subprocess.CalledProcessError:
             raise ConvertError(
                 "Failed to convert metadata using 'make testinfo.desc'.")
@@ -500,8 +498,7 @@ def read(
             with open(testinfo_path, encoding='utf-8') as testinfo_file:
                 testinfo = testinfo_file.read()
         except OSError:
-            raise ConvertError("Unable to open '{}'.".format(
-                testinfo_path))
+            raise ConvertError(f"Unable to open '{testinfo_path}'.")
 
     # restraint
     if restraint_file:
@@ -967,8 +964,7 @@ def read_nitrate_case(
     if testcase.tester:
         # Full 'Name Surname <[email protected]>' form
         if testcase.tester.name is not None:
-            data['contact'] = '{} <{}>'.format(
-                testcase.tester.name, testcase.tester.email)
+            data['contact'] = f'{testcase.tester.name} <{testcase.tester.email}>'
         else:
             if makefile_data is None or 'contact' not in makefile_data:
                 # Otherwise use just the email address

tmt/steps/provision/testcloud.py

@@ -331,7 +331,7 @@ def prepare_ssh_key(self, key_type: Optional[str] = None) -> None:
         # Generate new ssh key pair
         else:
             self.debug('Generating an ssh key.')
-            key_name = "id_{}".format(key_type if key_type is not None else 'rsa')
+            key_name = f"id_{key_type if key_type is not None else 'rsa'}"
             self.key = [self.workdir / key_name]
             command = Command("ssh-keygen", "-f", str(self.key[0]), "-N", "")
             if key_type is not None:

tmt/utils.py

@@ -1133,7 +1133,7 @@ def _check_or_create_workdir_root_with_perms() -> None:
 
             # Generated unique id or fail, has to be atomic call
             for id_bit in range(1, WORKDIR_MAX + 1):
-                directory = 'run-{}'.format(str(id_bit).rjust(3, '0'))
+                directory = f"run-{str(id_bit).rjust(3, '0')}"
                 workdir = workdir_root / directory
                 try:
                     # Call is atomic, no race possible
@@ -2534,7 +2534,7 @@ def format(
     """
     indent_string = (indent + 1) * ' '
     # Key
-    output = '{} '.format(str(key).rjust(indent, ' '))
+    output = f"{str(key).rjust(indent, ' ')} "
     if key_color is not None:
         output = style(output, fg=key_color)
     # Bool
@@ -2593,8 +2593,7 @@ def create_directory(
         path.mkdir(exist_ok=True, parents=True)
         say(f"Directory '{path}' created.")
     except OSError as error:
-        raise FileError("Failed to create {} '{}' ({})".format(
-            name, path, error)) from error
+        raise FileError(f"Failed to create {name} '{path}' ({error})") from error
 
 
 def create_file(
@@ -2623,8 +2622,7 @@ def create_file(
         say(f"{name.capitalize()} '{path}' {action}.")
         path.chmod(mode)
     except OSError as error:
-        raise FileError("Failed to create {} '{}' ({})".format(
-            name, path, error))
+        raise FileError(f"Failed to create {name} '{path}' ({error})")
 
 
 # Avoid multiple subprocess calls for the same url
@@ -3327,16 +3325,14 @@ def _load(self, text: str) -> None:
                 "Unable to detect StructuredField version")
         self.version(int(version_match.groups()[0]))
         log.debug(
-            "Detected StructuredField version {}".format(
-                self.version()))
+            f"Detected StructuredField version {self.version()}")
         # Convert to dictionary, remove escapes and save the order
         keys = parts[1::2]
         escape = re.compile(r"^\[structured-field-escape\]", re.MULTILINE)
         values = [escape.sub("", value) for value in parts[2::2]]
         for key, value in zip(keys, values):
             self.set(key, value)
-        log.debug("Parsed sections:\n{}".format(
-            pprint.pformat(self._sections)))
+        log.debug(f"Parsed sections:\n{pprint.pformat(self._sections)}")
 
     def _save_version_zero(self) -> str:
         """ Save version 0 format """
@@ -3363,8 +3359,8 @@ def _save(self) -> str:
         if self:
             result.append(
                 "[structured-field-start]\n"
-                "This is StructuredField version {}. "
-                "Please, edit with care.\n".format(self._version))
+                f"This is StructuredField version {self._version}. "
+                "Please, edit with care.\n")
             for section, content in self.iterate():
                 result.append("[{}]\n{}".format(section, escape.sub(
                     "[structured-field-escape]\\1", content)))
@@ -3492,8 +3488,7 @@ def get(
             return self._read_section(content)[item]
         except KeyError:
             raise StructuredFieldError(
-                "Unable to read '{!r}' from section '{!r}'".format(
-                    ascii(item), ascii(section)))
+                f"Unable to read '{ascii(item)!r}' from section '{ascii(section)!r}'")
 
     def set(self, section: str, content: Any,
             item: Optional[str] = None) -> None: