Use f-strings for simple string formatting

docs/pip_sphinxext.py

@@ -25,7 +25,7 @@ def run(self):
             cmd_prefix = cmd_prefix.strip('"')
             cmd_prefix = cmd_prefix.strip("'")
         usage = dedent(
-            cmd.usage.replace('%prog', '{} {}'.format(cmd_prefix, cmd.name))
+            cmd.usage.replace('%prog', f'{cmd_prefix} {cmd.name}')
         ).strip()
         node = nodes.literal_block(usage, usage)
         return [node]
@@ -63,7 +63,7 @@ def _format_option(self, option, cmd_name=None):
             line += option._long_opts[0]
         if option.takes_value():
             metavar = option.metavar or option.dest.lower()
-            line += " <{}>".format(metavar.lower())
+            line += f" <{metavar.lower()}>"
         # fix defaults
         opt_help = option.help.replace('%default', str(option.default))
         # fix paths with sys.prefix
@@ -123,7 +123,7 @@ def determine_opt_prefix(self, opt_name):
             if cmd.cmd_opts.has_option(opt_name):
                 return command
 
-        raise KeyError('Could not identify prefix of opt {}'.format(opt_name))
+        raise KeyError(f'Could not identify prefix of opt {opt_name}')
 
     def process_options(self):
         for option in SUPPORTED_OPTIONS:

src/pip/_internal/cli/base_command.py

@@ -55,7 +55,7 @@ def __init__(self, name, summary, isolated=False):
         super().__init__()
         parser_kw = {
             'usage': self.usage,
-            'prog': '{} {}'.format(get_prog(), name),
+            'prog': f'{get_prog()} {name}',
             'formatter': UpdatingDefaultsHelpFormatter(),
             'add_help_option': False,
             'name': name,
@@ -70,7 +70,7 @@ def __init__(self, name, summary, isolated=False):
         self.tempdir_registry = None  # type: Optional[TempDirRegistry]
 
         # Commands should add options to this option group
-        optgroup_name = '{} Options'.format(self.name.capitalize())
+        optgroup_name = f'{self.name.capitalize()} Options'
         self.cmd_opts = optparse.OptionGroup(self.parser, optgroup_name)
 
         # Add the general options

src/pip/_internal/cli/cmdoptions.py

@@ -46,7 +46,7 @@ def raise_option_error(parser, option, msg):
       option: an Option instance.
       msg: the error text.
     """
-    msg = '{} error: {}'.format(option, msg)
+    msg = f'{option} error: {msg}'
     msg = textwrap.fill(' '.join(msg.split()))
     parser.error(msg)
 

src/pip/_internal/cli/main.py

@@ -57,7 +57,7 @@ def main(args=None):
     try:
         cmd_name, cmd_args = parse_command(args)
     except PipError as exc:
-        sys.stderr.write("ERROR: {}".format(exc))
+        sys.stderr.write(f"ERROR: {exc}")
         sys.stderr.write(os.linesep)
         sys.exit(1)
 

src/pip/_internal/cli/main_parser.py

@@ -83,9 +83,9 @@ def parse_command(args):
     if cmd_name not in commands_dict:
         guess = get_similar_commands(cmd_name)
 
-        msg = ['unknown command "{}"'.format(cmd_name)]
+        msg = [f'unknown command "{cmd_name}"']
         if guess:
-            msg.append('maybe you meant "{}"'.format(guess))
+            msg.append(f'maybe you meant "{guess}"')
 
         raise CommandError(' - '.join(msg))
 

src/pip/_internal/cli/parser.py

@@ -82,7 +82,7 @@ def format_description(self, description):
             description = description.rstrip()
             # dedent, then reindent
             description = self.indent_lines(textwrap.dedent(description), "  ")
-            description = '{}:\n{}\n'.format(label, description)
+            description = f'{label}:\n{description}\n'
             return description
         else:
             return ''
@@ -168,7 +168,7 @@ def check_default(self, option, key, val):
         try:
             return option.check_value(key, val)
         except optparse.OptionValueError as exc:
-            print("An error occurred during configuration: {}".format(exc))
+            print(f"An error occurred during configuration: {exc}")
             sys.exit(3)
 
     def _get_ordered_configuration_items(self):
@@ -279,4 +279,4 @@ def get_default_values(self):
 
     def error(self, msg):
         self.print_usage(sys.stderr)
-        self.exit(UNKNOWN_ERROR, "{}\n".format(msg))
+        self.exit(UNKNOWN_ERROR, f"{msg}\n")

src/pip/_internal/cli/progress_bars.py

@@ -152,7 +152,7 @@ def download_speed(self):
     def pretty_eta(self):
         # type: () -> str
         if self.eta:  # type: ignore
-            return "eta {}".format(self.eta_td)  # type: ignore
+            return f"eta {self.eta_td}"  # type: ignore
         return ""
 
     def iter(self, it):  # type: ignore

src/pip/_internal/commands/cache.py

@@ -154,7 +154,7 @@ def format_for_human(self, files):
         for filename in files:
             wheel = os.path.basename(filename)
             size = filesystem.format_file_size(filename)
-            results.append(' - {} ({})'.format(wheel, size))
+            results.append(f' - {wheel} ({size})')
         logger.info('Cache contents:\n')
         logger.info('\n'.join(sorted(results)))
 

src/pip/_internal/commands/configuration.py

@@ -221,7 +221,7 @@ def print_env_var_values(self):
         write_output("%s:", 'env_var')
         with indent_log():
             for key, value in sorted(self.configuration.get_environ_vars()):
-                env_var = 'PIP_{}'.format(key.upper())
+                env_var = f'PIP_{key.upper()}'
                 write_output("%s=%r", env_var, value)
 
     def open_in_editor(self, options, args):

src/pip/_internal/commands/debug.py

@@ -66,7 +66,7 @@ def get_module_from_module_name(module_name):
         module_name = 'pkg_resources'
 
     __import__(
-        'pip._vendor.{}'.format(module_name),
+        f'pip._vendor.{module_name}',
         globals(),
         locals(),
         level=0
@@ -126,7 +126,7 @@ def show_tags(options):
     formatted_target = target_python.format_given()
     suffix = ''
     if formatted_target:
-        suffix = ' (target: {})'.format(formatted_target)
+        suffix = f' (target: {formatted_target})'
 
     msg = 'Compatible tags: {}{}'.format(len(tags), suffix)
     logger.info(msg)

src/pip/_internal/commands/help.py

@@ -32,9 +32,9 @@ def run(self, options, args):
         if cmd_name not in commands_dict:
             guess = get_similar_commands(cmd_name)
 
-            msg = ['unknown command "{}"'.format(cmd_name)]
+            msg = [f'unknown command "{cmd_name}"']
             if guess:
-                msg.append('maybe you meant "{}"'.format(guess))
+                msg.append(f'maybe you meant "{guess}"')
 
             raise CommandError(' - '.join(msg))
 

src/pip/_internal/configuration.py

@@ -164,7 +164,7 @@ def get_value(self, key):
         try:
             return self._dictionary[key]
         except KeyError:
-            raise ConfigurationError("No such key - {}".format(key))
+            raise ConfigurationError(f"No such key - {key}")
 
     def set_value(self, key, value):
         # type: (str, Any) -> None
@@ -193,7 +193,7 @@ def unset_value(self, key):
 
         assert self.load_only
         if key not in self._config[self.load_only]:
-            raise ConfigurationError("No such key - {}".format(key))
+            raise ConfigurationError(f"No such key - {key}")
 
         fname, parser = self._get_parser_to_modify()
 
@@ -403,4 +403,4 @@ def _mark_as_modified(self, fname, parser):
 
     def __repr__(self):
         # type: () -> str
-        return "{}({!r})".format(self.__class__.__name__, self._dictionary)
+        return f"{self.__class__.__name__}({self._dictionary!r})"

src/pip/_internal/distributions/sdist.py

@@ -52,7 +52,7 @@ def _raise_conflicts(conflicting_with, conflicting_reqs):
                 requirement=self.req,
                 conflicting_with=conflicting_with,
                 description=', '.join(
-                    '{} is incompatible with {}'.format(installed, wanted)
+                    f'{installed} is incompatible with {wanted}'
                     for installed, wanted in sorted(conflicting)
                 )
             )

src/pip/_internal/exceptions.py

@@ -203,11 +203,11 @@ def body(self):
             its link already populated by the resolver's _populate_link().
 
         """
-        return '    {}'.format(self._requirement_name())
+        return f'    {self._requirement_name()}'
 
     def __str__(self):
         # type: () -> str
-        return '{}\n{}'.format(self.head, self.body())
+        return f'{self.head}\n{self.body()}'
 
     def _requirement_name(self):
         # type: () -> str
@@ -364,8 +364,8 @@ def __init__(self, reason="could not be loaded", fname=None, error=None):
     def __str__(self):
         # type: () -> str
         if self.fname is not None:
-            message_part = " in {}.".format(self.fname)
+            message_part = f" in {self.fname}."
         else:
             assert self.error is not None
-            message_part = ".\n{}\n".format(self.error)
-        return "Configuration file {}{}".format(self.reason, message_part)
+            message_part = f".\n{self.error}\n"
+        return f"Configuration file {self.reason}{message_part}"

src/pip/_internal/index/collector.py

@@ -448,7 +448,7 @@ def _get_html_page(link, session=None):
         reason += str(exc)
         _handle_get_page_fail(link, reason, meth=logger.info)
     except requests.ConnectionError as exc:
-        _handle_get_page_fail(link, "connection error: {}".format(exc))
+        _handle_get_page_fail(link, f"connection error: {exc}")
     except requests.Timeout:
         _handle_get_page_fail(link, "timed out")
     else:
@@ -657,7 +657,7 @@ def collect_links(self, project_name):
             ),
         ]
         for link in url_locations:
-            lines.append('* {}'.format(link))
+            lines.append(f'* {link}')
         logger.debug('\n'.join(lines))
 
         return CollectedLinks(

src/pip/_internal/index/package_finder.py

@@ -161,7 +161,7 @@ def evaluate_link(self, link):
         version = None
         if link.is_yanked and not self._allow_yanked:
             reason = link.yanked_reason or '<none given>'
-            return (False, 'yanked for reason: {}'.format(reason))
+            return (False, f'yanked for reason: {reason}')
 
         if link.egg_fragment:
             egg_info = link.egg_fragment
@@ -171,7 +171,7 @@ def evaluate_link(self, link):
             if not ext:
                 return (False, 'not a file')
             if ext not in SUPPORTED_EXTENSIONS:
-                return (False, 'unsupported archive format: {}'.format(ext))
+                return (False, f'unsupported archive format: {ext}')
             if "binary" not in self._formats and ext == WHEEL_EXTENSION:
                 reason = 'No binaries permitted for {}'.format(
                     self.project_name)
@@ -204,15 +204,15 @@ def evaluate_link(self, link):
 
         # This should be up by the self.ok_binary check, but see issue 2700.
         if "source" not in self._formats and ext != WHEEL_EXTENSION:
-            reason = 'No sources permitted for {}'.format(self.project_name)
+            reason = f'No sources permitted for {self.project_name}'
             return (False, reason)
 
         if not version:
             version = _extract_version_from_fragment(
                 egg_info, self._canonical_name,
             )
         if not version:
-            reason = 'Missing project version for {}'.format(self.project_name)
+            reason = f'Missing project version for {self.project_name}'
             return (False, reason)
 
         match = self._py_version_re.search(version)
@@ -983,7 +983,7 @@ def _find_name_version_sep(fragment, canonical_name):
             continue
         if canonicalize_name(fragment[:i]) == canonical_name:
             return i
-    raise ValueError("{} does not match {}".format(fragment, canonical_name))
+    raise ValueError(f"{fragment} does not match {canonical_name}")
 
 
 def _extract_version_from_fragment(fragment, canonical_name):

src/pip/_internal/locations.py

@@ -111,8 +111,8 @@ def distutils_scheme(
     # NOTE: setting user or home has the side-effect of creating the home dir
     # or user base for installations during finalize_options()
     # ideally, we'd prefer a scheme class that has no side-effects.
-    assert not (user and prefix), "user={} prefix={}".format(user, prefix)
-    assert not (home and prefix), "home={} prefix={}".format(home, prefix)
+    assert not (user and prefix), f"user={user} prefix={prefix}"
+    assert not (home and prefix), f"home={home} prefix={prefix}"
     i.user = user or i.user
     if user or home:
         i.prefix = ""
@@ -138,7 +138,7 @@ def distutils_scheme(
             i.prefix,
             'include',
             'site',
-            'python{}'.format(get_major_minor_version()),
+            f'python{get_major_minor_version()}',
             dist_name,
         )
 

src/pip/_internal/models/direct_url.py

@@ -46,7 +46,7 @@ def _get_required(d, expected_type, key, default=None):
     # type: (Dict[str, Any], Type[T], str, Optional[T]) -> T
     value = _get(d, expected_type, key, default)
     if value is None:
-        raise DirectUrlValidationError("{} must have a value".format(key))
+        raise DirectUrlValidationError(f"{key} must have a value")
     return value
 
 

src/pip/_internal/models/link.py

@@ -83,7 +83,7 @@ def __init__(
     def __str__(self):
         # type: () -> str
         if self.requires_python:
-            rp = ' (requires-python:{})'.format(self.requires_python)
+            rp = f' (requires-python:{self.requires_python})'
         else:
             rp = ''
         if self.comes_from:
@@ -94,7 +94,7 @@ def __str__(self):
 
     def __repr__(self):
         # type: () -> str
-        return '<Link {}>'.format(self)
+        return f'<Link {self}>'
 
     @property
     def url(self):

src/pip/_internal/models/target_python.py

@@ -86,7 +86,7 @@ def format_given(self):
             ('implementation', self.implementation),
         ]
         return ' '.join(
-            '{}={!r}'.format(key, value) for key, value in key_values
+            f'{key}={value!r}' for key, value in key_values
             if value is not None
         )
 

src/pip/_internal/models/wheel.py

@@ -30,7 +30,7 @@ def __init__(self, filename):
         wheel_info = self.wheel_file_re.match(filename)
         if not wheel_info:
             raise InvalidWheelFilename(
-                "{} is not a valid wheel filename.".format(filename)
+                f"{filename} is not a valid wheel filename."
             )
         self.filename = filename
         self.name = wheel_info.group('name').replace('_', '-')

src/pip/_internal/network/auth.py

@@ -199,7 +199,7 @@ def _get_url_and_credentials(self, original_url):
             (username is not None and password is not None) or
             # Credentials were not found
             (username is None and password is None)
-        ), "Could not load credentials from url: {}".format(original_url)
+        ), f"Could not load credentials from url: {original_url}"
 
         return url, username, password
 
@@ -223,7 +223,7 @@ def __call__(self, req):
     # Factored out to allow for easy patching in tests
     def _prompt_for_password(self, netloc):
         # type: (str) -> Tuple[Optional[str], Optional[str], bool]
-        username = ask_input("User for {}: ".format(netloc))
+        username = ask_input(f"User for {netloc}: ")
         if not username:
             return None, None, False
         auth = get_keyring_auth(netloc, username)

src/pip/_internal/network/lazy_wheel.py

@@ -190,7 +190,7 @@ def _stream_response(self, start, end, base_headers=HEADERS):
         # type: (int, int, Dict[str, str]) -> Response
         """Return HTTP response to a range request from start to end."""
         headers = base_headers.copy()
-        headers['Range'] = 'bytes={}-{}'.format(start, end)
+        headers['Range'] = f'bytes={start}-{end}'
         # TODO: Get range requests to be correctly cached
         headers['Cache-Control'] = 'no-cache'
         return self._session.get(self._url, headers=headers, stream=True)

src/pip/_internal/network/session.py

@@ -317,9 +317,9 @@ def add_trusted_host(self, host, source=None, suppress_logging=False):
             string came from.
         """
         if not suppress_logging:
-            msg = 'adding trusted host: {!r}'.format(host)
+            msg = f'adding trusted host: {host!r}'
             if source is not None:
-                msg += ' (from {})'.format(source)
+                msg += f' (from {source})'
             logger.info(msg)
 
         host_port = parse_netloc(host)

src/pip/_internal/operations/build/metadata_legacy.py

@@ -26,7 +26,7 @@ def _find_egg_info(directory):
 
     if not filenames:
         raise InstallationError(
-            "No .egg-info directory found in {}".format(directory)
+            f"No .egg-info directory found in {directory}"
         )
 
     if len(filenames) > 1:

src/pip/_internal/operations/build/wheel.py

@@ -34,7 +34,7 @@ def build_wheel_pep517(
         logger.debug('Destination directory: %s', tempd)
 
         runner = runner_with_spinner_message(
-            'Building wheel for {} (PEP 517)'.format(name)
+            f'Building wheel for {name} (PEP 517)'
         )
         with backend.subprocess_runner(runner):
             wheel_name = backend.build_wheel(