Replace string formatting with f-strings

Signed-off-by: Aarni Koskela <akx@iki.fi>

docker/api/build.py

@@ -314,9 +314,8 @@ class BuildApiMixin:
                 auth_data[auth.INDEX_URL] = auth_data.get(auth.INDEX_NAME, {})
 
             log.debug(
-                'Sending auth config ({})'.format(
+                "Sending auth config (%s)",
-                    ', '.join(repr(k) for k in auth_data.keys())
+                ', '.join(repr(k) for k in auth_data),
-                )
             )
 
             if auth_data:
@@ -336,12 +335,9 @@ def process_dockerfile(dockerfile, path):
         abs_dockerfile = os.path.join(path, dockerfile)
         if constants.IS_WINDOWS_PLATFORM and path.startswith(
                 constants.WINDOWS_LONGPATH_PREFIX):
-            abs_dockerfile = '{}{}'.format(
+            normpath = os.path.normpath(
-                constants.WINDOWS_LONGPATH_PREFIX,
+                abs_dockerfile[len(constants.WINDOWS_LONGPATH_PREFIX):])
-                os.path.normpath(
+            abs_dockerfile = f'{constants.WINDOWS_LONGPATH_PREFIX}{normpath}'
-                    abs_dockerfile[len(constants.WINDOWS_LONGPATH_PREFIX):]
-                )
-            )
     if (os.path.splitdrive(path)[0] != os.path.splitdrive(abs_dockerfile)[0] or
             os.path.relpath(abs_dockerfile, path).startswith('..')):
         # Dockerfile not in context - read data to insert into tar later

docker/api/client.py

@@ -199,14 +199,13 @@ class APIClient(
             self._version = version
         if not isinstance(self._version, str):
             raise DockerException(
-                'Version parameter must be a string or None. Found {}'.format(
+                'Version parameter must be a string or None. '
-                    type(version).__name__
+                f'Found {type(version).__name__}'
-                )
             )
         if utils.version_lt(self._version, MINIMUM_DOCKER_API_VERSION):
             raise InvalidVersion(
-                'API versions below {} are no longer supported by this '
+                f'API versions below {MINIMUM_DOCKER_API_VERSION} are '
-                'library.'.format(MINIMUM_DOCKER_API_VERSION)
+                f'no longer supported by this library.'
             )
 
     def _retrieve_server_version(self):
@@ -248,19 +247,17 @@ class APIClient(
         for arg in args:
             if not isinstance(arg, str):
                 raise ValueError(
-                    'Expected a string but found {} ({}) '
+                    f'Expected a string but found {arg} ({type(arg)}) instead'
-                    'instead'.format(arg, type(arg))
                 )
 
         quote_f = partial(urllib.parse.quote, safe="/:")
         args = map(quote_f, args)
 
+        formatted_path = pathfmt.format(*args)
         if kwargs.get('versioned_api', True):
-            return '{}/v{}{}'.format(
+            return f'{self.base_url}/v{self._version}{formatted_path}'
-                self.base_url, self._version, pathfmt.format(*args)
-            )
         else:
-            return f'{self.base_url}{pathfmt.format(*args)}'
+            return f'{self.base_url}{formatted_path}'
 
     def _raise_for_status(self, response):
         """Raises stored :class:`APIError`, if one occurred."""

docker/api/container.py

@@ -861,8 +861,8 @@ class ContainerApiMixin:
                 params['since'] = since
             else:
                 raise errors.InvalidArgument(
-                    'since value should be datetime or positive int/float, '
+                    'since value should be datetime or positive int/float,'
-                    'not {}'.format(type(since))
+                    f' not {type(since)}'
                 )
 
         if until is not None:
@@ -878,8 +878,8 @@ class ContainerApiMixin:
                 params['until'] = until
             else:
                 raise errors.InvalidArgument(
-                    'until value should be datetime or positive int/float, '
+                    f'until value should be datetime or positive int/float, '
-                    'not {}'.format(type(until))
+                    f'not {type(until)}'
                 )
 
         url = self._url("/containers/{0}/logs", container)
@@ -951,7 +951,7 @@ class ContainerApiMixin:
             return port_settings.get(private_port)
 
         for protocol in ['tcp', 'udp', 'sctp']:
-            h_ports = port_settings.get(private_port + '/' + protocol)
+            h_ports = port_settings.get(f"{private_port}/{protocol}")
             if h_ports:
                 break
 

docker/api/service.py

@@ -7,9 +7,7 @@ def _check_api_features(version, task_template, update_config, endpoint_spec,
 
     def raise_version_error(param, min_version):
         raise errors.InvalidVersion(
-            '{} is not supported in API version < {}'.format(
+            f'{param} is not supported in API version < {min_version}'
-                param, min_version
-            )
         )
 
     if update_config is not None:

docker/auth.py

@@ -22,15 +22,15 @@ def resolve_repository_name(repo_name):
     index_name, remote_name = split_repo_name(repo_name)
     if index_name[0] == '-' or index_name[-1] == '-':
         raise errors.InvalidRepository(
-            'Invalid index name ({}). Cannot begin or end with a'
+            f'Invalid index name ({index_name}). '
-            ' hyphen.'.format(index_name)
+            'Cannot begin or end with a hyphen.'
         )
     return resolve_index_name(index_name), remote_name
 
 
 def resolve_index_name(index_name):
     index_name = convert_to_hostname(index_name)
-    if index_name == 'index.' + INDEX_NAME:
+    if index_name == f"index.{INDEX_NAME}":
         index_name = INDEX_NAME
     return index_name
 
@@ -99,9 +99,7 @@ class AuthConfig(dict):
         for registry, entry in entries.items():
             if not isinstance(entry, dict):
                 log.debug(
-                    'Config entry for key {} is not auth config'.format(
+                    f'Config entry for key {registry} is not auth config'
-                        registry
-                    )
                 )
                 # We sometimes fall back to parsing the whole config as if it
                 # was the auth config by itself, for legacy purposes. In that
@@ -109,17 +107,11 @@ class AuthConfig(dict):
                 # keys is not formatted properly.
                 if raise_on_error:
                     raise errors.InvalidConfigFile(
-                        'Invalid configuration for registry {}'.format(
+                        f'Invalid configuration for registry {registry}'
-                            registry
-                        )
                     )
                 return {}
             if 'identitytoken' in entry:
-                log.debug(
+                log.debug(f'Found an IdentityToken entry for registry {registry}')
-                    'Found an IdentityToken entry for registry {}'.format(
-                        registry
-                    )
-                )
                 conf[registry] = {
                     'IdentityToken': entry['identitytoken']
                 }
@@ -130,16 +122,15 @@ class AuthConfig(dict):
                 # a valid value in the auths config.
                 # https://github.com/docker/compose/issues/3265
                 log.debug(
-                    'Auth data for {} is absent. Client might be using a '
+                    f'Auth data for {registry} is absent. '
-                    'credentials store instead.'.format(registry)
+                    f'Client might be using a credentials store instead.'
                 )
                 conf[registry] = {}
                 continue
 
             username, password = decode_auth(entry['auth'])
             log.debug(
-                'Found entry (registry={}, username={})'
+                f'Found entry (registry={registry!r}, username={username!r})'
-                .format(repr(registry), repr(username))
             )
 
             conf[registry] = {

docker/context/api.py

@@ -113,8 +113,8 @@ class ContextAPI:
                         names.append(data["Name"])
                     except Exception as e:
                         raise errors.ContextException(
-                            "Failed to load metafile {}: {}".format(
+                            f"Failed to load metafile {filename}: {e}",
-                                filename, e))
+                        )
 
         contexts = [cls.DEFAULT_CONTEXT]
         for name in names:

docker/context/context.py

@@ -42,8 +42,9 @@ class Context:
         for k, v in endpoints.items():
             if not isinstance(v, dict):
                 # unknown format
-                raise ContextException("""Unknown endpoint format for
+                raise ContextException(
-                    context {}: {}""".format(name, v))
+                    f"Unknown endpoint format for context {name}: {v}",
+                )
 
             self.endpoints[k] = v
             if k != "docker":
@@ -96,8 +97,9 @@ class Context:
                 metadata = json.load(f)
         except (OSError, KeyError, ValueError) as e:
             # unknown format
-            raise Exception("""Detected corrupted meta file for
+            raise Exception(
-                context {} : {}""".format(name, e))
+                f"Detected corrupted meta file for context {name} : {e}"
+            )
 
         # for docker endpoints, set defaults for
         # Host and SkipTLSVerify fields

docker/credentials/errors.py

@@ -13,13 +13,5 @@ class InitializationError(StoreError):
 def process_store_error(cpe, program):
     message = cpe.output.decode('utf-8')
     if 'credentials not found in native keychain' in message:
-        return CredentialsNotFound(
+        return CredentialsNotFound(f'No matching credentials in {program}')
-            'No matching credentials in {}'.format(
+    return StoreError(f'Credentials store {program} exited with "{message}".')
-                program
-            )
-        )
-    return StoreError(
-        'Credentials store {} exited with "{}".'.format(
-            program, cpe.output.decode('utf-8').strip()
-        )
-    )

docker/credentials/store.py

@@ -20,9 +20,7 @@ class Store:
         self.environment = environment
         if self.exe is None:
             warnings.warn(
-                '{} not installed or not available in PATH'.format(
+                f'{self.program} not installed or not available in PATH'
-                    self.program
-                )
             )
 
     def get(self, server):
@@ -73,10 +71,8 @@ class Store:
     def _execute(self, subcmd, data_input):
         if self.exe is None:
             raise errors.StoreError(
-                    '{} not installed or not available in PATH'.format(
+                f'{self.program} not installed or not available in PATH'
-                        self.program
+            )
-                    )
-                )
         output = None
         env = create_environment_dict(self.environment)
         try:
@@ -88,14 +84,10 @@ class Store:
         except OSError as e:
             if e.errno == errno.ENOENT:
                 raise errors.StoreError(
-                    '{} not installed or not available in PATH'.format(
+                    f'{self.program} not installed or not available in PATH'
-                        self.program
-                    )
                 )
             else:
                 raise errors.StoreError(
-                    'Unexpected OS error "{}", errno={}'.format(
+                    f'Unexpected OS error "{e.strerror}", errno={e.errno}'
-                        e.strerror, e.errno
-                    )
                 )
         return output

docker/errors.py

@@ -54,14 +54,16 @@ class APIError(requests.exceptions.HTTPError, DockerException):
         message = super().__str__()
 
         if self.is_client_error():
-            message = '{} Client Error for {}: {}'.format(
+            message = (
-                self.response.status_code, self.response.url,
+                f'{self.response.status_code} Client Error for '
-                self.response.reason)
+                f'{self.response.url}: {self.response.reason}'
+            )
 
         elif self.is_server_error():
-            message = '{} Server Error for {}: {}'.format(
+            message = (
-                self.response.status_code, self.response.url,
+                f'{self.response.status_code} Server Error for '
-                self.response.reason)
+                f'{self.response.url}: {self.response.reason}'
+            )
 
         if self.explanation:
             message = f'{message} ("{self.explanation}")'
@@ -142,10 +144,10 @@ class ContainerError(DockerException):
         self.stderr = stderr
 
         err = f": {stderr}" if stderr is not None else ""
-        msg = ("Command '{}' in image '{}' returned non-zero exit "
+        super().__init__(
-               "status {}{}").format(command, image, exit_status, err)
+            f"Command '{command}' in image '{image}' "
-
+            f"returned non-zero exit status {exit_status}{err}"
-        super().__init__(msg)
+        )
 
 
 class StreamParseError(RuntimeError):

docker/models/images.py

@@ -15,10 +15,8 @@ class Image(Model):
     An image on the server.
     """
     def __repr__(self):
-        return "<{}: '{}'>".format(
+        tag_str = "', '".join(self.tags)
-            self.__class__.__name__,
+        return f"<{self.__class__.__name__}: '{tag_str}'>"
-            "', '".join(self.tags),
-        )
 
     @property
     def labels(self):
@@ -471,9 +469,8 @@ class ImageCollection(Collection):
             # to be pulled.
             pass
         if not all_tags:
-            return self.get('{0}{2}{1}'.format(
+            sep = '@' if tag.startswith('sha256:') else ':'
-                repository, tag, '@' if tag.startswith('sha256:') else ':'
+            return self.get(f'{repository}{sep}{tag}')
-            ))
         return self.list(repository)
 
     def push(self, repository, tag=None, **kwargs):

docker/models/resource.py

@@ -64,9 +64,10 @@ class Collection:
 
     def __call__(self, *args, **kwargs):
         raise TypeError(
-            "'{}' object is not callable. You might be trying to use the old "
+            f"'{self.__class__.__name__}' object is not callable. "
-            "(pre-2.0) API - use docker.APIClient if so."
+            "You might be trying to use the old (pre-2.0) API - "
-            .format(self.__class__.__name__))
+            "use docker.APIClient if so."
+        )
 
     def list(self):
         raise NotImplementedError
@@ -88,5 +89,4 @@ class Collection:
         elif isinstance(attrs, dict):
             return self.model(attrs=attrs, client=self.client, collection=self)
         else:
-            raise Exception("Can't create %s from %s" %
+            raise Exception(f"Can't create {self.model.__name__} from {attrs}")
-                            (self.model.__name__, attrs))

docker/transport/unixconn.py

@@ -55,7 +55,7 @@ class UnixHTTPAdapter(BaseHTTPAdapter):
                  max_pool_size=constants.DEFAULT_MAX_POOL_SIZE):
         socket_path = socket_url.replace('http+unix://', '')
         if not socket_path.startswith('/'):
-            socket_path = '/' + socket_path
+            socket_path = f"/{socket_path}"
         self.socket_path = socket_path
         self.timeout = timeout
         self.max_pool_size = max_pool_size

docker/types/containers.py

@@ -652,25 +652,25 @@ class HostConfig(dict):
 
 
 def host_config_type_error(param, param_value, expected):
-    error_msg = 'Invalid type for {0} param: expected {1} but found {2}'
+    return TypeError(
-    return TypeError(error_msg.format(param, expected, type(param_value)))
+        f'Invalid type for {param} param: expected {expected} '
+        f'but found {type(param_value)}'
+    )
 
 
 def host_config_version_error(param, version, less_than=True):
     operator = '<' if less_than else '>'
-    error_msg = '{0} param is not supported in API versions {1} {2}'
+    return errors.InvalidVersion(
-    return errors.InvalidVersion(error_msg.format(param, operator, version))
+        f'{param} param is not supported in API versions {operator} {version}',
-
+    )
 
 def host_config_value_error(param, param_value):
-    error_msg = 'Invalid value for {0} param: {1}'
+    return ValueError(f'Invalid value for {param} param: {param_value}')
-    return ValueError(error_msg.format(param, param_value))
 
 
 def host_config_incompatible_error(param, param_value, incompatible_param):
-    error_msg = '\"{1}\" {0} is incompatible with {2}'
     return errors.InvalidArgument(
-        error_msg.format(param, param_value, incompatible_param)
+        f'\"{param_value}\" {param} is incompatible with {incompatible_param}'
     )
 
 

docker/types/services.py

@@ -370,8 +370,8 @@ def _convert_generic_resources_dict(generic_resources):
         return generic_resources
     if not isinstance(generic_resources, dict):
         raise errors.InvalidArgument(
-            'generic_resources must be a dict or a list'
+            'generic_resources must be a dict or a list '
-            ' (found {})'.format(type(generic_resources))
+            f'(found {type(generic_resources)})'
         )
     resources = []
     for kind, value in generic_resources.items():
@@ -381,9 +381,9 @@ def _convert_generic_resources_dict(generic_resources):
         elif isinstance(value, str):
             resource_type = 'NamedResourceSpec'
         else:
+            kv = {kind: value}
             raise errors.InvalidArgument(
-                'Unsupported generic resource reservation '
+                f'Unsupported generic resource reservation type: {kv}'
-                'type: {}'.format({kind: value})
             )
         resources.append({
             resource_type: {'Kind': kind, 'Value': value}
@@ -764,8 +764,8 @@ class PlacementPreference(dict):
     def __init__(self, strategy, descriptor):
         if strategy != 'spread':
             raise errors.InvalidArgument(
-                'PlacementPreference strategy value is invalid ({}):'
+                f'PlacementPreference strategy value is invalid ({strategy}): '
-                ' must be "spread".'.format(strategy)
+                'must be "spread".'
             )
         self['Spread'] = {'SpreadDescriptor': descriptor}
 

docker/utils/build.py

@@ -42,7 +42,7 @@ def exclude_paths(root, patterns, dockerfile=None):
     if dockerfile is None:
         dockerfile = 'Dockerfile'
 
-    patterns.append('!' + dockerfile)
+    patterns.append(f"!{dockerfile}")
     pm = PatternMatcher(patterns)
     return set(pm.walk(root))
 
@@ -180,7 +180,7 @@ class PatternMatcher:
                 fpath = os.path.join(
                     os.path.relpath(current_dir, root), f
                 )
-                if fpath.startswith('.' + os.path.sep):
+                if fpath.startswith(f".{os.path.sep}"):
                     fpath = fpath[2:]
                 match = self.matches(fpath)
                 if not match:

docker/utils/decorators.py

@@ -27,9 +27,7 @@ def minimum_version(version):
         def wrapper(self, *args, **kwargs):
             if utils.version_lt(self._version, version):
                 raise errors.InvalidVersion(
-                    '{} is not available for version < {}'.format(
+                    f'{f.__name__} is not available for version < {version}',
-                        f.__name__, version
-                    )
                 )
             return f(self, *args, **kwargs)
         return wrapper

docker/utils/fnmatch.py

@@ -79,18 +79,18 @@ def translate(pat):
                     i = i + 1
                 if i >= n:
                     # is "**EOF" - to align with .gitignore just accept all
-                    res = res + '.*'
+                    res = f"{res}.*"
                 else:
                     # is "**"
                     # Note that this allows for any # of /'s (even 0) because
                     # the .* will eat everything, even /'s
-                    res = res + '(.*/)?'
+                    res = f"{res}(.*/)?"
             else:
                 # is "*" so map it to anything but "/"
-                res = res + '[^/]*'
+                res = f"{res}[^/]*"
         elif c == '?':
             # "?" is any char except "/"
-            res = res + '[^/]'
+            res = f"{res}[^/]"
         elif c == '[':
             j = i
             if j < n and pat[j] == '!':
@@ -100,16 +100,16 @@ def translate(pat):
             while j < n and pat[j] != ']':
                 j = j + 1
             if j >= n:
-                res = res + '\\['
+                res = f"{res}\\["
             else:
                 stuff = pat[i:j].replace('\\', '\\\\')
                 i = j + 1
                 if stuff[0] == '!':
-                    stuff = '^' + stuff[1:]
+                    stuff = f"^{stuff[1:]}"
                 elif stuff[0] == '^':
-                    stuff = '\\' + stuff
+                    stuff = f"\\{stuff}"
                 res = f'{res}[{stuff}]'
         else:
             res = res + re.escape(c)
 
-    return res + '$'
+    return f"{res}$"

docker/utils/ports.py

@@ -49,7 +49,7 @@ def port_range(start, end, proto, randomly_available_port=False):
     if not end:
         return [start + proto]
     if randomly_available_port:
-        return [f'{start}-{end}' + proto]
+        return [f"{start}-{end}{proto}"]
     return [str(port) + proto for port in range(int(start), int(end) + 1)]
 
 

docker/utils/proxy.py

@@ -69,5 +69,9 @@ class ProxyConfig(dict):
         return proxy_env + environment
 
     def __str__(self):
-        return 'ProxyConfig(http={}, https={}, ftp={}, no_proxy={})'.format(
+        return (
-            self.http, self.https, self.ftp, self.no_proxy)
+            'ProxyConfig('
+            f'http={self.http}, https={self.https}, '
+            f'ftp={self.ftp}, no_proxy={self.no_proxy}'
+            ')'
+        )

docker/utils/utils.py

@@ -127,8 +127,7 @@ def convert_volume_binds(binds):
         if isinstance(v, dict):
             if 'ro' in v and 'mode' in v:
                 raise ValueError(
-                    'Binding cannot contain both "ro" and "mode": {}'
+                    f'Binding cannot contain both "ro" and "mode": {v!r}'
-                    .format(repr(v))
                 )
 
             bind = v['bind']
@@ -160,8 +159,8 @@ def convert_tmpfs_mounts(tmpfs):
 
     if not isinstance(tmpfs, list):
         raise ValueError(
-            'Expected tmpfs value to be either a list or a dict, found: {}'
+            'Expected tmpfs value to be either a list or a dict, '
-            .format(type(tmpfs).__name__)
+            f'found: {type(tmpfs).__name__}'
         )
 
     result = {}
@@ -175,8 +174,8 @@ def convert_tmpfs_mounts(tmpfs):
 
         else:
             raise ValueError(
-                "Expected item in tmpfs list to be a string, found: {}"
+                "Expected item in tmpfs list to be a string, "
-                .format(type(mount).__name__)
+                f"found: {type(mount).__name__}"
             )
 
         result[name] = options
@@ -218,9 +217,9 @@ def parse_host(addr, is_win32=False, tls=False):
 
     parsed_url = urlparse(addr)
     proto = parsed_url.scheme
-    if not proto or any([x not in string.ascii_letters + '+' for x in proto]):
+    if not proto or any([x not in f"{string.ascii_letters}+" for x in proto]):
         # https://bugs.python.org/issue754016
-        parsed_url = urlparse('//' + addr, 'tcp')
+        parsed_url = urlparse(f"//{addr}", 'tcp')
         proto = 'tcp'
 
     if proto == 'fd':
@@ -256,15 +255,14 @@ def parse_host(addr, is_win32=False, tls=False):
 
     if parsed_url.path and proto == 'ssh':
         raise errors.DockerException(
-            'Invalid bind address format: no path allowed for this protocol:'
+            f'Invalid bind address format: no path allowed for this protocol: {addr}'
-            ' {}'.format(addr)
         )
     else:
         path = parsed_url.path
         if proto == 'unix' and parsed_url.hostname is not None:
             # For legacy reasons, we consider unix://path
             # to be valid and equivalent to unix:///path
-            path = '/'.join((parsed_url.hostname, path))
+            path = f"{parsed_url.hostname}/{path}"
 
     netloc = parsed_url.netloc
     if proto in ('tcp', 'ssh'):
@@ -272,8 +270,7 @@ def parse_host(addr, is_win32=False, tls=False):
         if port <= 0:
             if proto != 'ssh':
                 raise errors.DockerException(
-                    'Invalid bind address format: port is required:'
+                    f'Invalid bind address format: port is required: {addr}'
-                    ' {}'.format(addr)
                 )
             port = 22
             netloc = f'{parsed_url.netloc}:{port}'
@@ -283,7 +280,7 @@ def parse_host(addr, is_win32=False, tls=False):
 
     # Rewrite schemes to fit library internals (requests adapters)
     if proto == 'tcp':
-        proto = 'http{}'.format('s' if tls else '')
+        proto = f"http{'s' if tls else ''}"
     elif proto == 'unix':
         proto = 'http+unix'
 
@@ -419,17 +416,16 @@ def parse_bytes(s):
             digits = float(digits_part)
         except ValueError:
             raise errors.DockerException(
-                'Failed converting the string value for memory ({}) to'
+                'Failed converting the string value for memory '
-                ' an integer.'.format(digits_part)
+                f'({digits_part}) to an integer.'
             )
 
         # Reconvert to long for the final result
         s = int(digits * units[suffix])
     else:
         raise errors.DockerException(
-            'The specified value for memory ({}) should specify the'
+            f'The specified value for memory ({s}) should specify the units. '
-            ' units. The postfix should be one of the `b` `k` `m` `g`'
+            'The postfix should be one of the `b` `k` `m` `g` characters'
-            ' characters'.format(s)
         )
 
     return s
@@ -465,8 +461,7 @@ def parse_env_file(env_file):
                 environment[k] = v
             else:
                 raise errors.DockerException(
-                    'Invalid line in environment file {}:\n{}'.format(
+                    f'Invalid line in environment file {env_file}:\n{line}')
-                        env_file, line))
 
     return environment
 

docs/conf.py

@@ -56,7 +56,7 @@ master_doc = 'index'
 # General information about the project.
 project = 'Docker SDK for Python'
 year = datetime.datetime.now().year
-copyright = '%d Docker Inc' % year
+copyright = f'{year} Docker Inc'
 author = 'Docker Inc'
 
 # The version info for the project you're documenting, acts as replacement for

tests/helpers.py

@@ -80,7 +80,7 @@ def wait_on_condition(condition, delay=0.1, timeout=40):
     start_time = time.time()
     while not condition():
         if time.time() - start_time > timeout:
-            raise AssertionError("Timeout: %s" % condition)
+            raise AssertionError(f"Timeout: {condition}")
         time.sleep(delay)
 
 

tests/integration/api_client_test.py

@@ -72,6 +72,4 @@ class UnixconnTest(unittest.TestCase):
             client.close()
             del client
 
-            assert len(w) == 0, "No warnings produced: {}".format(
+            assert len(w) == 0, f"No warnings produced: {w[0].message}"
-                w[0].message
-            )

tests/integration/api_container_test.py

@@ -666,9 +666,7 @@ class ArchiveTest(BaseAPIIntegrationTest):
             test_file.seek(0)
             ctnr = self.client.create_container(
                 TEST_IMG,
-                'cat {}'.format(
+                f"cat {os.path.join('/vol1/', os.path.basename(test_file.name))}",
-                    os.path.join('/vol1/', os.path.basename(test_file.name))
-                ),
                 volumes=['/vol1']
             )
             self.tmp_containers.append(ctnr)
@@ -826,7 +824,7 @@ class LogsTest(BaseAPIIntegrationTest):
         exitcode = self.client.wait(id)['StatusCode']
         assert exitcode == 0
         logs = self.client.logs(id)
-        assert logs == (snippet + '\n').encode(encoding='ascii')
+        assert logs == f"{snippet}\n".encode(encoding='ascii')
 
     def test_logs_tail_option(self):
         snippet = '''Line1
@@ -857,7 +855,7 @@ Line2'''
         exitcode = self.client.wait(id)['StatusCode']
         assert exitcode == 0
 
-        assert logs == (snippet + '\n').encode(encoding='ascii')
+        assert logs == f"{snippet}\n".encode(encoding='ascii')
 
     @pytest.mark.timeout(5)
     @pytest.mark.skipif(os.environ.get('DOCKER_HOST', '').startswith('ssh://'),
@@ -878,7 +876,7 @@ Line2'''
         for chunk in generator:
             logs += chunk
 
-        assert logs == (snippet + '\n').encode(encoding='ascii')
+        assert logs == f"{snippet}\n".encode(encoding='ascii')
 
     def test_logs_with_dict_instead_of_id(self):
         snippet = 'Flowering Nights (Sakuya Iyazoi)'
@@ -891,7 +889,7 @@ Line2'''
         exitcode = self.client.wait(id)['StatusCode']
         assert exitcode == 0
         logs = self.client.logs(container)
-        assert logs == (snippet + '\n').encode(encoding='ascii')
+        assert logs == f"{snippet}\n".encode(encoding='ascii')
 
     def test_logs_with_tail_0(self):
         snippet = 'Flowering Nights (Sakuya Iyazoi)'
@@ -920,7 +918,7 @@ Line2'''
         logs_until_1 = self.client.logs(container, until=1)
         assert logs_until_1 == b''
         logs_until_now = self.client.logs(container, datetime.now())
-        assert logs_until_now == (snippet + '\n').encode(encoding='ascii')
+        assert logs_until_now == f"{snippet}\n".encode(encoding='ascii')
 
 
 class DiffTest(BaseAPIIntegrationTest):
@@ -1086,7 +1084,7 @@ class PortTest(BaseAPIIntegrationTest):
 
             ip, host_port = port_binding['HostIp'], port_binding['HostPort']
 
-            port_binding = port if not protocol else port + "/" + protocol
+            port_binding = port if not protocol else f"{port}/{protocol}"
             assert ip == port_bindings[port_binding][0]
             assert host_port == port_bindings[port_binding][1]
 

tests/integration/base.py

@@ -103,8 +103,7 @@ class BaseAPIIntegrationTest(BaseIntegrationTest):
         if exitcode != 0:
             output = self.client.logs(container)
             raise Exception(
-                "Container exited with code {}:\n{}"
+                f"Container exited with code {exitcode}:\n{output}")
-                .format(exitcode, output))
 
         return container
 

tests/integration/credentials/store_test.py

@@ -22,7 +22,7 @@ class TestStore:
     def setup_method(self):
         self.tmp_keys = []
         if sys.platform.startswith('linux'):
-            if shutil.which('docker-credential-' + DEFAULT_LINUX_STORE):
+            if shutil.which(f"docker-credential-{DEFAULT_LINUX_STORE}"):
                 self.store = Store(DEFAULT_LINUX_STORE)
             elif shutil.which('docker-credential-pass'):
                 self.store = Store('pass')

tests/integration/models_containers_test.py

@@ -49,7 +49,7 @@ class ContainerCollectionTest(BaseIntegrationTest):
 
         container = client.containers.run(
             "alpine", "sh -c 'echo \"hello\" > /insidecontainer/test'",
-            volumes=["%s:/insidecontainer" % path],
+            volumes=[f"{path}:/insidecontainer"],
             detach=True
         )
         self.tmp_containers.append(container.id)
@@ -58,7 +58,7 @@ class ContainerCollectionTest(BaseIntegrationTest):
         name = "container_volume_test"
         out = client.containers.run(
             "alpine", "cat /insidecontainer/test",
-            volumes=["%s:/insidecontainer" % path],
+            volumes=[f"{path}:/insidecontainer"],
             name=name
         )
         self.tmp_containers.append(name)

tests/ssh/base.py

@@ -110,8 +110,7 @@ class BaseAPIIntegrationTest(BaseIntegrationTest):
         if exitcode != 0:
             output = self.client.logs(container)
             raise Exception(
-                "Container exited with code {}:\n{}"
+                f"Container exited with code {exitcode}:\n{output}")
-                .format(exitcode, output))
 
         return container
 

tests/unit/api_build_test.py

@@ -89,7 +89,7 @@ class BuildTest(BaseAPIClientTest):
 
         fake_request.assert_called_with(
             'POST',
-            url_prefix + 'build',
+            f"{url_prefix}build",
             stream=True,
             data=None,
             headers=expected_headers,
@@ -193,10 +193,10 @@ class BuildTest(BaseAPIClientTest):
             'foo/Dockerfile.foo', None
         )
         assert process_dockerfile(
-            '../Dockerfile', pre(base + '\\foo')
+            '../Dockerfile', pre(f"{base}\\foo")
         )[1] is not None
         assert process_dockerfile(
-            '../baz/Dockerfile.baz', pre(base + '/baz')
+            '../baz/Dockerfile.baz', pre(f"{base}/baz")
         ) == ('../baz/Dockerfile.baz', None)
 
     def test_process_dockerfile(self):
@@ -218,8 +218,8 @@ class BuildTest(BaseAPIClientTest):
             'foo/Dockerfile.foo', None
         )
         assert process_dockerfile(
-            '../Dockerfile', base + '/foo'
+            '../Dockerfile', f"{base}/foo"
         )[1] is not None
-        assert process_dockerfile('../baz/Dockerfile.baz', base + '/baz') == (
+        assert process_dockerfile('../baz/Dockerfile.baz', f"{base}/baz") == (
             '../baz/Dockerfile.baz', None
         )

tests/unit/api_exec_test.py

@@ -32,9 +32,7 @@ class ExecTest(BaseAPIClientTest):
         self.client.exec_start(fake_api.FAKE_EXEC_ID)
 
         args = fake_request.call_args
-        assert args[0][1] == url_prefix + 'exec/{}/start'.format(
+        assert args[0][1] == f"{url_prefix}exec/{fake_api.FAKE_EXEC_ID}/start"
-            fake_api.FAKE_EXEC_ID
-        )
 
         assert json.loads(args[1]['data']) == {
             'Tty': False,
@@ -51,9 +49,7 @@ class ExecTest(BaseAPIClientTest):
         self.client.exec_start(fake_api.FAKE_EXEC_ID, detach=True)
 
         args = fake_request.call_args
-        assert args[0][1] == url_prefix + 'exec/{}/start'.format(
+        assert args[0][1] == f"{url_prefix}exec/{fake_api.FAKE_EXEC_ID}/start"
-            fake_api.FAKE_EXEC_ID
-        )
 
         assert json.loads(args[1]['data']) == {
             'Tty': False,
@@ -68,16 +64,14 @@ class ExecTest(BaseAPIClientTest):
         self.client.exec_inspect(fake_api.FAKE_EXEC_ID)
 
         args = fake_request.call_args
-        assert args[0][1] == url_prefix + 'exec/{}/json'.format(
+        assert args[0][1] == f"{url_prefix}exec/{fake_api.FAKE_EXEC_ID}/json"
-            fake_api.FAKE_EXEC_ID
-        )
 
     def test_exec_resize(self):
         self.client.exec_resize(fake_api.FAKE_EXEC_ID, height=20, width=60)
 
         fake_request.assert_called_with(
             'POST',
-            url_prefix + f'exec/{fake_api.FAKE_EXEC_ID}/resize',
+            f"{url_prefix}exec/{fake_api.FAKE_EXEC_ID}/resize",
             params={'h': 20, 'w': 60},
             timeout=DEFAULT_TIMEOUT_SECONDS
         )

tests/unit/api_image_test.py

@@ -21,7 +21,7 @@ class ImageTest(BaseAPIClientTest):
 
         fake_request.assert_called_with(
             'GET',
-            url_prefix + 'images/json',
+            f"{url_prefix}images/json",
             params={'only_ids': 0, 'all': 1},
             timeout=DEFAULT_TIMEOUT_SECONDS
         )
@@ -31,7 +31,7 @@ class ImageTest(BaseAPIClientTest):
 
         fake_request.assert_called_with(
             'GET',
-            url_prefix + 'images/json',
+            f"{url_prefix}images/json",
             params={'only_ids': 0, 'all': 0,
                     'filters': '{"reference": ["foo:bar"]}'},
             timeout=DEFAULT_TIMEOUT_SECONDS
@@ -42,7 +42,7 @@ class ImageTest(BaseAPIClientTest):
 
         fake_request.assert_called_with(
             'GET',
-            url_prefix + 'images/json',
+            f"{url_prefix}images/json",
             params={'only_ids': 1, 'all': 1},
             timeout=DEFAULT_TIMEOUT_SECONDS
         )
@@ -52,7 +52,7 @@ class ImageTest(BaseAPIClientTest):
 
         fake_request.assert_called_with(
             'GET',
-            url_prefix + 'images/json',
+            f"{url_prefix}images/json",
             params={'only_ids': 1, 'all': 0},
             timeout=DEFAULT_TIMEOUT_SECONDS
         )
@@ -62,7 +62,7 @@ class ImageTest(BaseAPIClientTest):
 
         fake_request.assert_called_with(
             'GET',
-            url_prefix + 'images/json',
+            f"{url_prefix}images/json",
             params={'only_ids': 0, 'all': 0,
                     'filters': '{"dangling": ["true"]}'},
             timeout=DEFAULT_TIMEOUT_SECONDS
@@ -72,7 +72,7 @@ class ImageTest(BaseAPIClientTest):
         self.client.pull('joffrey/test001')
 
         args = fake_request.call_args
-        assert args[0][1] == url_prefix + 'images/create'
+        assert args[0][1] == f"{url_prefix}images/create"
         assert args[1]['params'] == {
             'tag': 'latest', 'fromImage': 'joffrey/test001'
         }
@@ -82,7 +82,7 @@ class ImageTest(BaseAPIClientTest):
         self.client.pull('joffrey/test001', stream=True)
 
         args = fake_request.call_args
-        assert args[0][1] == url_prefix + 'images/create'
+        assert args[0][1] == f"{url_prefix}images/create"
         assert args[1]['params'] == {
             'tag': 'latest', 'fromImage': 'joffrey/test001'
         }
@@ -93,7 +93,7 @@ class ImageTest(BaseAPIClientTest):
 
         fake_request.assert_called_with(
             'POST',
-            url_prefix + 'commit',
+            f"{url_prefix}commit",
             data='{}',
             headers={'Content-Type': 'application/json'},
             params={
@@ -112,7 +112,7 @@ class ImageTest(BaseAPIClientTest):
 
         fake_request.assert_called_with(
             'DELETE',
-            url_prefix + 'images/' + fake_api.FAKE_IMAGE_ID,
+            f"{url_prefix}images/{fake_api.FAKE_IMAGE_ID}",
             params={'force': False, 'noprune': False},
             timeout=DEFAULT_TIMEOUT_SECONDS
         )
@@ -122,7 +122,7 @@ class ImageTest(BaseAPIClientTest):
 
         fake_request.assert_called_with(
             'GET',
-            url_prefix + 'images/test_image/history',
+            f"{url_prefix}images/test_image/history",
             timeout=DEFAULT_TIMEOUT_SECONDS
         )
 
@@ -135,7 +135,7 @@ class ImageTest(BaseAPIClientTest):
 
         fake_request.assert_called_with(
             'POST',
-            url_prefix + 'images/create',
+            f"{url_prefix}images/create",
             params={
                 'repo': fake_api.FAKE_REPO_NAME,
                 'tag': fake_api.FAKE_TAG_NAME,
@@ -156,7 +156,7 @@ class ImageTest(BaseAPIClientTest):
 
         fake_request.assert_called_with(
             'POST',
-            url_prefix + 'images/create',
+            f"{url_prefix}images/create",
             params={
                 'repo': fake_api.FAKE_REPO_NAME,
                 'tag': fake_api.FAKE_TAG_NAME,
@@ -178,7 +178,7 @@ class ImageTest(BaseAPIClientTest):
 
         fake_request.assert_called_with(
             'POST',
-            url_prefix + 'images/create',
+            f"{url_prefix}images/create",
             params={
                 'repo': fake_api.FAKE_REPO_NAME,
                 'tag': fake_api.FAKE_TAG_NAME,
@@ -193,7 +193,7 @@ class ImageTest(BaseAPIClientTest):
 
         fake_request.assert_called_with(
             'GET',
-            url_prefix + 'images/test_image/json',
+            f"{url_prefix}images/test_image/json",
             timeout=DEFAULT_TIMEOUT_SECONDS
         )
 
@@ -211,7 +211,7 @@ class ImageTest(BaseAPIClientTest):
 
         fake_request.assert_called_with(
             'POST',
-            url_prefix + 'images/test_image/push',
+            f"{url_prefix}images/test_image/push",
             params={
                 'tag': None
             },
@@ -230,7 +230,7 @@ class ImageTest(BaseAPIClientTest):
 
         fake_request.assert_called_with(
             'POST',
-            url_prefix + 'images/test_image/push',
+            f"{url_prefix}images/test_image/push",
             params={
                 'tag': fake_api.FAKE_TAG_NAME,
             },
@@ -254,7 +254,7 @@ class ImageTest(BaseAPIClientTest):
 
         fake_request.assert_called_with(
             'POST',
-            url_prefix + 'images/test_image/push',
+            f"{url_prefix}images/test_image/push",
             params={
                 'tag': fake_api.FAKE_TAG_NAME,
             },
@@ -272,7 +272,7 @@ class ImageTest(BaseAPIClientTest):
 
         fake_request.assert_called_with(
             'POST',
-            url_prefix + 'images/test_image/push',
+            f"{url_prefix}images/test_image/push",
             params={
                 'tag': None
             },
@@ -287,7 +287,7 @@ class ImageTest(BaseAPIClientTest):
 
         fake_request.assert_called_with(
             'POST',
-            url_prefix + 'images/' + fake_api.FAKE_IMAGE_ID + '/tag',
+            f"{url_prefix}images/{fake_api.FAKE_IMAGE_ID}/tag",
             params={
                 'tag': None,
                 'repo': 'repo',
@@ -305,7 +305,7 @@ class ImageTest(BaseAPIClientTest):
 
         fake_request.assert_called_with(
             'POST',
-            url_prefix + 'images/' + fake_api.FAKE_IMAGE_ID + '/tag',
+            f"{url_prefix}images/{fake_api.FAKE_IMAGE_ID}/tag",
             params={
                 'tag': 'tag',
                 'repo': 'repo',
@@ -320,7 +320,7 @@ class ImageTest(BaseAPIClientTest):
 
         fake_request.assert_called_with(
             'POST',
-            url_prefix + 'images/' + fake_api.FAKE_IMAGE_ID + '/tag',
+            f"{url_prefix}images/{fake_api.FAKE_IMAGE_ID}/tag",
             params={
                 'tag': None,
                 'repo': 'repo',
@@ -334,7 +334,7 @@ class ImageTest(BaseAPIClientTest):
 
         fake_request.assert_called_with(
             'GET',
-            url_prefix + 'images/' + fake_api.FAKE_IMAGE_ID + '/get',
+            f"{url_prefix}images/{fake_api.FAKE_IMAGE_ID}/get",
             stream=True,
             timeout=DEFAULT_TIMEOUT_SECONDS
         )
@@ -344,7 +344,7 @@ class ImageTest(BaseAPIClientTest):
 
         fake_request.assert_called_with(
             'POST',
-            url_prefix + 'images/load',
+            f"{url_prefix}images/load",
             data='Byte Stream....',
             stream=True,
             params={},
@@ -356,7 +356,7 @@ class ImageTest(BaseAPIClientTest):
 
         fake_request.assert_called_with(
             'POST',
-            url_prefix + 'images/load',
+            f"{url_prefix}images/load",
             data='Byte Stream....',
             stream=True,
             params={'quiet': True},

tests/unit/api_network_test.py

@@ -28,7 +28,7 @@ class NetworkTest(BaseAPIClientTest):
         with mock.patch('docker.api.client.APIClient.get', get):
             assert self.client.networks() == networks
 
-            assert get.call_args[0][0] == url_prefix + 'networks'
+            assert get.call_args[0][0] == f"{url_prefix}networks"
 
             filters = json.loads(get.call_args[1]['params']['filters'])
             assert not filters
@@ -54,7 +54,7 @@ class NetworkTest(BaseAPIClientTest):
             result = self.client.create_network('foo')
             assert result == network_data
 
-            assert post.call_args[0][0] == url_prefix + 'networks/create'
+            assert post.call_args[0][0] == f"{url_prefix}networks/create"
 
             assert json.loads(post.call_args[1]['data']) == {"Name": "foo"}
 
@@ -97,7 +97,7 @@ class NetworkTest(BaseAPIClientTest):
             self.client.remove_network(network_id)
 
         args = delete.call_args
-        assert args[0][0] == url_prefix + f'networks/{network_id}'
+        assert args[0][0] == f"{url_prefix}networks/{network_id}"
 
     def test_inspect_network(self):
         network_id = 'abc12345'
@@ -117,7 +117,7 @@ class NetworkTest(BaseAPIClientTest):
             assert result == network_data
 
         args = get.call_args
-        assert args[0][0] == url_prefix + f'networks/{network_id}'
+        assert args[0][0] == f"{url_prefix}networks/{network_id}"
 
     def test_connect_container_to_network(self):
         network_id = 'abc12345'
@@ -135,7 +135,7 @@ class NetworkTest(BaseAPIClientTest):
             )
 
         assert post.call_args[0][0] == (
-            url_prefix + f'networks/{network_id}/connect'
+            f"{url_prefix}networks/{network_id}/connect"
         )
 
         assert json.loads(post.call_args[1]['data']) == {
@@ -158,7 +158,7 @@ class NetworkTest(BaseAPIClientTest):
                 container={'Id': container_id}, net_id=network_id)
 
         assert post.call_args[0][0] == (
-            url_prefix + f'networks/{network_id}/disconnect'
+            f"{url_prefix}networks/{network_id}/disconnect"
         )
         assert json.loads(post.call_args[1]['data']) == {
             'Container': container_id

tests/unit/api_test.py

@@ -86,9 +86,7 @@ def fake_read_from_socket(self, response, stream, tty=False, demux=False):
 
 
 url_base = f'{fake_api.prefix}/'
-url_prefix = '{}v{}/'.format(
+url_prefix = f'{url_base}v{docker.constants.DEFAULT_DOCKER_API_VERSION}/'
-    url_base,
-    docker.constants.DEFAULT_DOCKER_API_VERSION)
 
 
 class BaseAPIClientTest(unittest.TestCase):
@@ -130,22 +128,18 @@ class DockerApiTest(BaseAPIClientTest):
 
     def test_url_valid_resource(self):
         url = self.client._url('/hello/{0}/world', 'somename')
-        assert url == '{}{}'.format(url_prefix, 'hello/somename/world')
+        assert url == f"{url_prefix}hello/somename/world"
 
         url = self.client._url(
             '/hello/{0}/world/{1}', 'somename', 'someothername'
         )
-        assert url == '{}{}'.format(
+        assert url == f"{url_prefix}hello/somename/world/someothername"
-            url_prefix, 'hello/somename/world/someothername'
-        )
 
         url = self.client._url('/hello/{0}/world', 'some?name')
-        assert url == '{}{}'.format(url_prefix, 'hello/some%3Fname/world')
+        assert url == f"{url_prefix}hello/some%3Fname/world"
 
         url = self.client._url("/images/{0}/push", "localhost:5000/image")
-        assert url == '{}{}'.format(
+        assert url == f"{url_prefix}images/localhost:5000/image/push"
-            url_prefix, 'images/localhost:5000/image/push'
-        )
 
     def test_url_invalid_resource(self):
         with pytest.raises(ValueError):
@@ -153,20 +147,20 @@ class DockerApiTest(BaseAPIClientTest):
 
     def test_url_no_resource(self):
         url = self.client._url('/simple')
-        assert url == '{}{}'.format(url_prefix, 'simple')
+        assert url == f"{url_prefix}simple"
 
     def test_url_unversioned_api(self):
         url = self.client._url(
             '/hello/{0}/world', 'somename', versioned_api=False
         )
-        assert url == '{}{}'.format(url_base, 'hello/somename/world')
+        assert url == f"{url_base}hello/somename/world"
 
     def test_version(self):
         self.client.version()
 
         fake_request.assert_called_with(
             'GET',
-            url_prefix + 'version',
+            f"{url_prefix}version",
             timeout=DEFAULT_TIMEOUT_SECONDS
         )
 
@@ -175,7 +169,7 @@ class DockerApiTest(BaseAPIClientTest):
 
         fake_request.assert_called_with(
             'GET',
-            url_base + 'version',
+            f"{url_base}version",
             timeout=DEFAULT_TIMEOUT_SECONDS
         )
 
@@ -194,7 +188,7 @@ class DockerApiTest(BaseAPIClientTest):
 
         fake_request.assert_called_with(
             'GET',
-            url_prefix + 'info',
+            f"{url_prefix}info",
             timeout=DEFAULT_TIMEOUT_SECONDS
         )
 
@@ -203,7 +197,7 @@ class DockerApiTest(BaseAPIClientTest):
 
         fake_request.assert_called_with(
             'GET',
-            url_prefix + 'images/search',
+            f"{url_prefix}images/search",
             params={'term': 'busybox'},
             timeout=DEFAULT_TIMEOUT_SECONDS
         )
@@ -212,7 +206,7 @@ class DockerApiTest(BaseAPIClientTest):
         self.client.login('sakuya', 'izayoi')
         args = fake_request.call_args
         assert args[0][0] == 'POST'
-        assert args[0][1] == url_prefix + 'auth'
+        assert args[0][1] == f"{url_prefix}auth"
         assert json.loads(args[1]['data']) == {
             'username': 'sakuya', 'password': 'izayoi'
         }
@@ -229,7 +223,7 @@ class DockerApiTest(BaseAPIClientTest):
 
         fake_request.assert_called_with(
             'GET',
-            url_prefix + 'events',
+            f"{url_prefix}events",
             params={'since': None, 'until': None, 'filters': None},
             stream=True,
             timeout=None
@@ -245,7 +239,7 @@ class DockerApiTest(BaseAPIClientTest):
 
         fake_request.assert_called_with(
             'GET',
-            url_prefix + 'events',
+            f"{url_prefix}events",
             params={
                 'since': ts - 10,
                 'until': ts + 10,
@@ -264,7 +258,7 @@ class DockerApiTest(BaseAPIClientTest):
         expected_filters = docker.utils.convert_filters(filters)
         fake_request.assert_called_with(
             'GET',
-            url_prefix + 'events',
+            f"{url_prefix}events",
             params={
                 'since': None,
                 'until': None,
@@ -318,7 +312,7 @@ class DockerApiTest(BaseAPIClientTest):
 
         fake_request.assert_called_with(
             'DELETE',
-            url_prefix + 'containers/' + fake_api.FAKE_CONTAINER_ID,
+            f"{url_prefix}containers/{fake_api.FAKE_CONTAINER_ID}",
             params={'v': False, 'link': True, 'force': False},
             timeout=DEFAULT_TIMEOUT_SECONDS
         )
@@ -332,7 +326,7 @@ class DockerApiTest(BaseAPIClientTest):
             self.client.create_host_config(security_opt='wrong')
 
     def test_stream_helper_decoding(self):
-        status_code, content = fake_api.fake_responses[url_prefix + 'events']()
+        status_code, content = fake_api.fake_responses[f"{url_prefix}events"]()
         content_str = json.dumps(content)
         content_str = content_str.encode('utf-8')
         body = io.BytesIO(content_str)
@@ -443,7 +437,7 @@ class UnixSocketStreamTest(unittest.TestCase):
         lines = []
         for i in range(0, 50):
             line = str(i).encode()
-            lines += [('%x' % len(line)).encode(), line]
+            lines += [f'{len(line):x}'.encode(), line]
         lines.append(b'0')
         lines.append(b'')
 
@@ -454,7 +448,7 @@ class UnixSocketStreamTest(unittest.TestCase):
         ) + b'\r\n'.join(lines)
 
         with APIClient(
-                base_url="http+unix://" + self.socket_file,
+                base_url=f"http+unix://{self.socket_file}",
                 version=DEFAULT_DOCKER_API_VERSION) as client:
             for i in range(5):
                 try:
@@ -490,8 +484,7 @@ class TCPSocketStreamTest(unittest.TestCase):
         cls.thread = threading.Thread(target=cls.server.serve_forever)
         cls.thread.daemon = True
         cls.thread.start()
-        cls.address = 'http://{}:{}'.format(
+        cls.address = f'http://{socket.gethostname()}:{cls.server.server_address[1]}'
-            socket.gethostname(), cls.server.server_address[1])
 
     @classmethod
     def teardown_class(cls):
@@ -600,7 +593,7 @@ class UserAgentTest(unittest.TestCase):
         self.patcher = mock.patch.object(
             APIClient,
             'send',
-            return_value=fake_resp("GET", "%s/version" % fake_api.prefix)
+            return_value=fake_resp("GET", f"{fake_api.prefix}/version")
         )
         self.mock_send = self.patcher.start()
 
@@ -613,7 +606,7 @@ class UserAgentTest(unittest.TestCase):
 
         assert self.mock_send.call_count == 1
         headers = self.mock_send.call_args[0][0].headers
-        expected = 'docker-sdk-python/%s' % docker.__version__
+        expected = f'docker-sdk-python/{docker.__version__}'
         assert headers['User-Agent'] == expected
 
     def test_custom_user_agent(self):

tests/unit/api_volume_test.py

@@ -14,7 +14,7 @@ class VolumeTest(BaseAPIClientTest):
         args = fake_request.call_args
 
         assert args[0][0] == 'GET'
-        assert args[0][1] == url_prefix + 'volumes'
+        assert args[0][1] == f"{url_prefix}volumes"
 
     def test_list_volumes_and_filters(self):
         volumes = self.client.volumes(filters={'dangling': True})
@@ -23,7 +23,7 @@ class VolumeTest(BaseAPIClientTest):
         args = fake_request.call_args
 
         assert args[0][0] == 'GET'
-        assert args[0][1] == url_prefix + 'volumes'
+        assert args[0][1] == f"{url_prefix}volumes"
         assert args[1] == {'params': {'filters': '{"dangling": ["true"]}'},
                            'timeout': 60}
 
@@ -37,7 +37,7 @@ class VolumeTest(BaseAPIClientTest):
         args = fake_request.call_args
 
         assert args[0][0] == 'POST'
-        assert args[0][1] == url_prefix + 'volumes/create'
+        assert args[0][1] == f"{url_prefix}volumes/create"
         assert json.loads(args[1]['data']) == {'Name': name}
 
     @requires_api_version('1.23')
@@ -63,7 +63,7 @@ class VolumeTest(BaseAPIClientTest):
         args = fake_request.call_args
 
         assert args[0][0] == 'POST'
-        assert args[0][1] == url_prefix + 'volumes/create'
+        assert args[0][1] == f"{url_prefix}volumes/create"
         data = json.loads(args[1]['data'])
         assert 'Driver' in data
         assert data['Driver'] == driver_name

tests/unit/auth_test.py

@@ -290,9 +290,10 @@ class LoadConfigTest(unittest.TestCase):
         folder = tempfile.mkdtemp()
         self.addCleanup(shutil.rmtree, folder)
 
-        dockercfg_path = os.path.join(folder,
+        dockercfg_path = os.path.join(
-                                      '.{}.dockercfg'.format(
+            folder,
-                                          random.randrange(100000)))
+            f'.{random.randrange(100000)}.dockercfg',
+        )
         registry = 'https://your.private.registry.io'
         auth_ = base64.b64encode(b'sakuya:izayoi').decode('ascii')
         config = {

tests/unit/client_test.py

@@ -85,10 +85,7 @@ class ClientTest(unittest.TestCase):
         mock_obj.return_value.urlopen.return_value.status = 200
         client.ping()
 
-        base_url = "{base_url}/v{version}/_ping".format(
+        base_url = f"{client.api.base_url}/v{client.api._version}/_ping"
-            base_url=client.api.base_url,
-            version=client.api._version
-        )
 
         mock_obj.assert_called_once_with(base_url,
                                          "/var/run/docker.sock",
@@ -124,10 +121,7 @@ class ClientTest(unittest.TestCase):
         mock_obj.return_value.urlopen.return_value.status = 200
         client.ping()
 
-        base_url = "{base_url}/v{version}/_ping".format(
+        base_url = f"{client.api.base_url}/v{client.api._version}/_ping"
-            base_url=client.api.base_url,
-            version=client.api._version
-        )
 
         mock_obj.assert_called_once_with(base_url,
                                          "/var/run/docker.sock",
@@ -198,10 +192,7 @@ class FromEnvTest(unittest.TestCase):
         mock_obj.return_value.urlopen.return_value.status = 200
         client.ping()
 
-        base_url = "{base_url}/v{version}/_ping".format(
+        base_url = f"{client.api.base_url}/v{client.api._version}/_ping"
-            base_url=client.api.base_url,
-            version=client.api._version
-        )
 
         mock_obj.assert_called_once_with(base_url,
                                          "/var/run/docker.sock",
@@ -235,10 +226,7 @@ class FromEnvTest(unittest.TestCase):
         mock_obj.return_value.urlopen.return_value.status = 200
         client.ping()
 
-        base_url = "{base_url}/v{version}/_ping".format(
+        base_url = f"{client.api.base_url}/v{client.api._version}/_ping"
-            base_url=client.api.base_url,
-            version=client.api._version
-        )
 
         mock_obj.assert_called_once_with(base_url,
                                          "/var/run/docker.sock",

tests/unit/fake_api.py

@@ -617,17 +617,11 @@ fake_responses = {
     get_fake_volume_list,
     (f'{prefix}/{CURRENT_VERSION}/volumes/create', 'POST'):
     get_fake_volume,
-    ('{1}/{0}/volumes/{2}'.format(
+    (f'{prefix}/{CURRENT_VERSION}/volumes/{FAKE_VOLUME_NAME}', 'GET'):
-        CURRENT_VERSION, prefix, FAKE_VOLUME_NAME
-    ), 'GET'):
     get_fake_volume,
-    ('{1}/{0}/volumes/{2}'.format(
+    (f'{prefix}/{CURRENT_VERSION}/volumes/{FAKE_VOLUME_NAME}', 'DELETE'):
-        CURRENT_VERSION, prefix, FAKE_VOLUME_NAME
-    ), 'DELETE'):
     fake_remove_volume,
-    ('{1}/{0}/nodes/{2}/update?version=1'.format(
+    (f'{prefix}/{CURRENT_VERSION}/nodes/{FAKE_NODE_ID}/update?version=1', 'POST'):
-        CURRENT_VERSION, prefix, FAKE_NODE_ID
-    ), 'POST'):
     post_fake_update_node,
     (f'{prefix}/{CURRENT_VERSION}/swarm/join', 'POST'):
     post_fake_join_swarm,
@@ -635,21 +629,13 @@ fake_responses = {
     get_fake_network_list,
     (f'{prefix}/{CURRENT_VERSION}/networks/create', 'POST'):
     post_fake_network,
-    ('{1}/{0}/networks/{2}'.format(
+    (f'{prefix}/{CURRENT_VERSION}/networks/{FAKE_NETWORK_ID}', 'GET'):
-        CURRENT_VERSION, prefix, FAKE_NETWORK_ID
-    ), 'GET'):
     get_fake_network,
-    ('{1}/{0}/networks/{2}'.format(
+    (f'{prefix}/{CURRENT_VERSION}/networks/{FAKE_NETWORK_ID}', 'DELETE'):
-        CURRENT_VERSION, prefix, FAKE_NETWORK_ID
-    ), 'DELETE'):
     delete_fake_network,
-    ('{1}/{0}/networks/{2}/connect'.format(
+    (f'{prefix}/{CURRENT_VERSION}/networks/{FAKE_NETWORK_ID}/connect', 'POST'):
-        CURRENT_VERSION, prefix, FAKE_NETWORK_ID
-    ), 'POST'):
     post_fake_network_connect,
-    ('{1}/{0}/networks/{2}/disconnect'.format(
+    (f'{prefix}/{CURRENT_VERSION}/networks/{FAKE_NETWORK_ID}/disconnect', 'POST'):
-        CURRENT_VERSION, prefix, FAKE_NETWORK_ID
-    ), 'POST'):
     post_fake_network_disconnect,
     f'{prefix}/{CURRENT_VERSION}/secrets/create':
     post_fake_secret,

tests/unit/swarm_test.py

@@ -20,7 +20,7 @@ class SwarmTest(BaseAPIClientTest):
         )
         args = fake_request.call_args
         assert args[0][1] == (
-            url_prefix + 'nodes/24ifsmvkjbyhk/update?version=1'
+            f"{url_prefix}nodes/24ifsmvkjbyhk/update?version=1"
         )
         assert json.loads(args[1]['data']) == node_spec
         assert args[1]['headers']['Content-Type'] == 'application/json'
@@ -45,7 +45,7 @@ class SwarmTest(BaseAPIClientTest):
 
         args = fake_request.call_args
 
-        assert (args[0][1] == url_prefix + 'swarm/join')
+        assert (args[0][1] == f"{url_prefix}swarm/join")
         assert (json.loads(args[1]['data']) == data)
         assert (args[1]['headers']['Content-Type'] == 'application/json')
 
@@ -64,6 +64,6 @@ class SwarmTest(BaseAPIClientTest):
 
         args = fake_request.call_args
 
-        assert (args[0][1] == url_prefix + 'swarm/join')
+        assert (args[0][1] == f"{url_prefix}swarm/join")
         assert (json.loads(args[1]['data']) == data)
         assert (args[1]['headers']['Content-Type'] == 'application/json')

tests/unit/utils_test.py

@@ -486,9 +486,9 @@ class PortsTest(unittest.TestCase):
     def test_split_port_with_protocol(self):
         for protocol in ['tcp', 'udp', 'sctp']:
             internal_port, external_port = split_port(
-                "127.0.0.1:1000:2000/" + protocol
+                f"127.0.0.1:1000:2000/{protocol}"
             )
-            assert internal_port == ["2000/" + protocol]
+            assert internal_port == [f"2000/{protocol}"]
             assert external_port == [("127.0.0.1", "1000")]
 
     def test_split_port_with_host_ip_no_port(self):