Use Python 3.6+ f-strings

Author: apragacz

docs/conf.py

@@ -28,13 +28,12 @@
 
 # -- Project information -----------------------------------------------------
 
-project = 'Django REST Registration'
-docs_title = '{project} documentation'.format(project=project)
-author = 'Andrzej Pragacz'
+project = "Django REST Registration"
+docs_title = f"{project} documentation"
+author = "Andrzej Pragacz"
 datetime_now = datetime.datetime.now()
 current_year = datetime_now
-copyright = '{current_year}, {author}'.format(  # noqa: E501 pylint: disable=redefined-builtin
-    author=author, current_year=current_year)
+copyright = f"{current_year}, {author}"  # pylint: disable=redefined-builtin
 version = rest_registration.__version__
 release = version
 
@@ -213,8 +212,7 @@
 }
 settings_fields_groups_map = settings_fields.SETTINGS_FIELDS_GROUPS_MAP
 for group_name, settings_fields in settings_fields_groups_map.items():
-    ctx_key = 'detailed_configuration__{group_name}'.format(
-        group_name=group_name)
+    ctx_key = f"detailed_configuration__{group_name}"
     jinja_contexts[ctx_key] = {
         'settings_fields': settings_fields,
         'generate_setting_refs': False,

examples/sharedlinks/sharedlinks-backend/links/models.py

@@ -14,7 +14,7 @@ class Link(models.Model):
     )
 
     def __str__(self):
-        return '{self.title} ({self.url})'.format(self=self)
+        return f"{self.title} ({self.url})"
 
     def get_num_of_positive_votes(self):
         return self.votes.filter(positive=True).count()
@@ -53,5 +53,4 @@ def __str__(self):
         else:
             vote = 'neutral'
 
-        return '{vote} vote for {self.link} by {self.voter}'.format(
-            vote=vote, self=self)
+        return f"{vote} vote for {self.link} by {self.voter}"

examples/sharedlinks/sharedlinks-backend/sharedlinks/settings.py

@@ -173,7 +173,7 @@
 
 
 def get_frontend_url(uri):
-    return 'http://localhost:3000{uri}'.format(uri=uri)
+    return f"http://localhost:3000{uri}"
 
 
 REST_REGISTRATION = {

pyproject.toml

@@ -111,7 +111,6 @@ disable = [
 	"line-too-long",
 	"ungrouped-imports",
 	"fixme",
-	"consider-using-f-string",
 ]
 
 [tool.pylint.reports]

rest_registration/api/views/base.py

@@ -27,9 +27,9 @@ def get_serializer_class(self) -> Type[Serializer]:
         (Eg. admins get full serialization, others get basic serialization)
         """
         assert self.serializer_class is not None, (
-            "'%s' should either include a `serializer_class` attribute, "
-            "or override the `get_serializer_class()` method."
-            % self.__class__.__name__
+            f"'{self.__class__.__name__}' should either include a "
+            f"`serializer_class` attribute, "
+            f"or override the `get_serializer_class()` method."
         )
 
         return self.serializer_class

rest_registration/enums.py

@@ -32,7 +32,7 @@ class ErrorCode(_BaseCheckCodeMixin, Enum):
     INVALID_AUTH_BACKENDS_CONFIG = 14
 
     def get_code_id(self) -> str:
-        return 'E{self.value:03d}'.format(self=self)
+        return f"E{self.value:03d}"
 
     def get_check_message_class(self) -> Type[CheckMessage]:
         return checks.Error
@@ -46,7 +46,7 @@ class WarningCode(_BaseCheckCodeMixin, Enum):
     DEPRECATION = 2
 
     def get_code_id(self) -> str:
-        return 'W{self.value:03d}'.format(self=self)
+        return f"W{self.value:03d}"
 
     def get_check_message_class(self) -> Type[CheckMessage]:
         return checks.Warning

rest_registration/signers/register.py

@@ -23,8 +23,7 @@ def _calculate_salt(self, data):
             # implies changed salt used when verifying the input data.
             verification_flag_field = get_user_setting('VERIFICATION_FLAG_FIELD')
             verification_flag = getattr(user, verification_flag_field)
-            salt = '{self.SALT_BASE}:{verification_flag}'.format(
-                self=self, verification_flag=verification_flag)
+            salt = f"{self.SALT_BASE}:{verification_flag}"
         else:
             salt = self.SALT_BASE
         return salt

rest_registration/signers/reset_password.py

@@ -22,8 +22,7 @@ def _calculate_salt(self, data):
             # was caused by previous password reset and the signature
             # is not valid anymore because changed password hash implies
             # changed salt used when verifying the input data.
-            salt = '{self.SALT_BASE}:{user_password_hash}'.format(
-                self=self, user_password_hash=user_password_hash)
+            salt = f"{self.SALT_BASE}:{user_password_hash}"
         else:
             salt = self.SALT_BASE
         return salt

rest_registration/utils/checks.py

@@ -17,7 +17,7 @@ class CheckCode:
     def get_full_code_id(self) -> str:
         app_name = self.get_app_name()
         code_id = self.get_code_id()
-        return '{app_name}.{code_id}'.format(app_name=app_name, code_id=code_id)
+        return f"{app_name}.{code_id}"
 
     def get_app_name(self) -> str:
         raise NotImplementedError()
@@ -81,8 +81,7 @@ def check_fun(
                 fun()
             except Exception as exc:  # pylint: disable=broad-except
                 exc_str = str(exc)
-                msg = '{error_message}: {exc_str}'.format(
-                    error_message=error_message, exc_str=exc_str)
+                msg = f"{error_message}: {exc_str}"
                 return [
                     message_cls(
                         msg,

rest_registration/utils/email.py

@@ -90,8 +90,8 @@ def parse_template_config(template_config_data: Dict[str, Any]) -> EmailTemplate
             )
     else:
         raise ImproperlyConfigured(
-            'Could not parse template config data: {template_config_data}'.format(  # noqa: E501
-                template_config_data=template_config_data))
+            f"Could not parse template config data: {template_config_data}",
+        )
 
     _validate_template_name_existence(config.subject_template_name)
     _validate_template_name_existence(config.text_body_template_name)
@@ -109,6 +109,6 @@ def _validate_template_name_existence(template_name: str) -> None:
         get_template(template_name)
     except TemplateDoesNotExist:
         raise ImproperlyConfigured(
-            'Template {template_name!r} does not exist; ensure that your'
-            ' Django TEMPLATES setting is configured correctly'.format(
-                template_name=template_name)) from None
+            f"Template {template_name!r} does not exist; ensure that your"
+            f" Django TEMPLATES setting is configured correctly",
+        ) from None

rest_registration/utils/html.py

@@ -43,7 +43,7 @@ def handle_endtag(self, tag: str) -> None:
         last_segment = last_paragraph[-1] if last_paragraph else None
         if (self._preserve_urls and
                 tag_info.name == 'a' and href and href != last_segment):
-            self._append_segment('({href})'.format(href=href))
+            self._append_segment(f"({href})")
 
         if tag == 'p':
             self._paragraphs.append([])
@@ -58,8 +58,7 @@ def handle_data(self, data: str) -> None:
             self._append_segment(data)
 
     def error(self, message: str) -> None:
-        raise ValueError("HTML parse error: {message}".format(
-            message=message))
+        raise ValueError(f"HTML parse error: {message}")
 
     def get_data(self) -> str:
         paragraph_texts = []

rest_registration/utils/nested_settings.py

@@ -43,9 +43,7 @@ def is_default(self, attr: str) -> bool:
 
     def __getattr__(self, attr: str) -> Any:
         if attr not in self.defaults.keys():
-            raise AttributeError(
-                "Invalid {self.root_setting_name} setting: '{attr}'".format(
-                    self=self, attr=attr))
+            raise AttributeError(f"Invalid {self.root_setting_name} setting: '{attr}'")
 
         try:
             # Check if present in user settings

rest_registration/utils/users.py

@@ -177,7 +177,7 @@ def get_user_field_obj(name: str) -> 'UserField':
 
 
 def get_user_setting(name: str) -> Any:
-    setting_name = 'USER_{name}'.format(name=name)
+    setting_name = f"USER_{name}"
     user_class = get_user_model()
     placeholder = object()
     value = getattr(user_class, name, placeholder)

rest_registration/utils/verification.py

@@ -36,7 +36,7 @@ def verify_signer_or_bad_request(signer: URLParamsSigner) -> None:
 def build_default_verification_url(signer: URLParamsSigner) -> str:
     base_url = signer.get_base_url()
     params = urlencode(signer.get_signed_data())
-    url = '{base_url}?{params}'.format(base_url=base_url, params=params)
+    url = f"{base_url}?{params}"
     if signer.request:
         url = signer.request.build_absolute_uri(url)
     return url

tests/doctest_utils.py

@@ -14,4 +14,4 @@ def _print_operator_test(first, second, op, fail_message_fmt):  # noqa: E501 pyl
             first=first,
             second=second,
             operator=op)
-        print('FAIL:\n{fail_msg}'.format(fail_msg=fail_msg))  # noqa: T201
+        print(f"FAIL:\n{fail_msg}")  # noqa: T201

tests/helpers/api_views.py

@@ -114,20 +114,15 @@ def _assert_response(
         expected_status_code=None):
     status_code = response.status_code
     if expected_status_code is not None:
-        msg_format = dedent("""\
+        msg = dedent(f"""\
             Response returned with HTTP code {status_code} but code {expected_status_code} was expected.
 
             Response body was {response.data}.""")  # noqa: E501
     else:
-        msg_format = dedent("""\
+        msg = dedent(f"""\
             Response unexpectedly returned with HTTP code {status_code}
 
             Response body was {response.data}.""")
-    msg = msg_format.format(
-        status_code=status_code,
-        expected_status_code=expected_status_code,
-        response=response,
-    )
     if expected_status_code is not None:
         assert status_code == expected_status_code, msg
     elif expected_valid_response:

tests/helpers/common.py

@@ -35,17 +35,14 @@ def create_test_user(**kwargs):
 
 
 def assert_len_equals(collection, expected_len, msg=None):
-    std_msg = "{collection} does not have length {expected_len}".format(
-        collection=collection,
-        expected_len=expected_len,
-    )
+    std_msg = f"{collection} does not have length {expected_len}"
     assert len(collection) == expected_len, format_assert_message(msg, std_msg)
 
 
 def format_assert_message(msg, standard_msg="assertion failed"):
     if msg is None:
         return standard_msg
-    return "{standard_msg} : {msg}".format(standard_msg=standard_msg, msg=msg)
+    return f"{standard_msg} : {msg}"
 
 
 USER_DEFAULT_FIELD_VALUES = {

tests/helpers/email.py

@@ -49,9 +49,5 @@ def is_set(self):
 
 def _assert_emails_sent(sent_emails, expected_num):
     num_of_sent_emails = len(sent_emails)
-    msg_format = "Expected {expected_num} emails to be sent, but found {num_of_sent_emails}"  # noqa: E501
-    msg = msg_format.format(
-        expected_num=expected_num,
-        num_of_sent_emails=num_of_sent_emails,
-    )
+    msg = f"Expected {expected_num} emails to be sent, but found {num_of_sent_emails}"
     assert num_of_sent_emails == expected_num, msg

tests/helpers/testcases.py

@@ -24,31 +24,17 @@ def create_test_user(self, **kwargs):
         return create_test_user(**kwargs)
 
     def assert_len_equals(self, collection, expected_len, msg=None):
-        std_msg_format = "{collection} does not have length {expected_len}"
-        std_msg = std_msg_format.format(
-            collection=collection,
-            expected_len=expected_len,
-        )
+        std_msg = f"{collection} does not have length {expected_len}"
         if len(collection) != expected_len:
             self.fail(self._formatMessage(msg, std_msg))
 
     def assert_is_between(self, value, start, end, msg=None):
-        std_msg_format = "{value} is not in range [{start}, {end})"
-        std_msg = std_msg_format.format(
-            value=value,
-            start=start,
-            end=end,
-        )
+        std_msg = f"{value} is not in range [{start}, {end})"
         if not start <= value < end:
             self.fail(self._formatMessage(msg, std_msg))
 
     def assert_is_not_between(self, value, start, end, msg=None):
-        std_msg_format = "{value} is unexpectedly in range [{start}, {end})"
-        std_msg = std_msg_format.format(
-            value=value,
-            start=start,
-            end=end,
-        )
+        std_msg = f"{value} is unexpectedly in range [{start}, {end})"
         if start <= value < end:
             self.fail(self._formatMessage(msg, std_msg))
 
@@ -62,11 +48,7 @@ def _assert_mails_sent(self, expected_num):
         with self.capture_sent_emails() as sent_emails:
             yield sent_emails
         num_of_sent_emails = len(sent_emails)
-        msg_format = "Expected {expected_num} emails to be sent, but found {num_of_sent_emails}"  # noqa: E501
-        msg = msg_format.format(
-            expected_num=expected_num,
-            num_of_sent_emails=num_of_sent_emails,
-        )
+        msg = f"Expected {expected_num} emails to be sent, but found {num_of_sent_emails}"  # noqa: E501
         self.assertEqual(num_of_sent_emails, expected_num, msg=msg)
 
     @contextlib.contextmanager
@@ -98,12 +80,7 @@ def _assert_urls_in_text(self, text, expected_num, line_url_pattern):
                 match_groupdict = match.groupdict()
                 urls.append(match_groupdict['url'])
         num_of_urls = len(urls)
-        msg_format = "Found {num_of_urls} urls instead of {expected_num} in:\n{text}"  # noqa: E501
-        msg = msg_format.format(
-            num_of_urls=num_of_urls,
-            expected_num=expected_num,
-            text=text,
-        )
+        msg = f"Found {num_of_urls} urls instead of {expected_num} in:\n{text}"
         self.assertEqual(num_of_urls, expected_num, msg=msg)
         return urls
 
@@ -133,7 +110,7 @@ def setUp(self):
     def full_view_name(self):
         assert self.APP_NAME
         assert self.VIEW_NAME
-        return '{self.APP_NAME}:{self.VIEW_NAME}'.format(self=self)
+        return f"{self.APP_NAME}:{self.VIEW_NAME}"
 
     @property
     def view_url(self):

tests/helpers/text.py

@@ -23,11 +23,6 @@ def _assert_urls_in_text(text, expected_num, line_url_pattern):
             match_groupdict = match.groupdict()
             urls.append(match_groupdict['url'])
     num_of_urls = len(urls)
-    msg_format = "Found {num_of_urls} urls instead of {expected_num} in:\n{text}"  # noqa: E501
-    msg = msg_format.format(
-        num_of_urls=num_of_urls,
-        expected_num=expected_num,
-        text=text,
-    )
+    msg = f"Found {num_of_urls} urls instead of {expected_num} in:\n{text}"
     assert num_of_urls == expected_num, msg
     return urls

tests/helpers/verification.py

@@ -47,9 +47,9 @@ def _parse_verification_url(
 
     for key, values in query.items():
         if not values:
-            raise ValueError("no values for '{key}".format(key=key))
+            raise ValueError(f"no values for {key!r}")
         if len(values) > 1:
-            raise ValueError("multiple values for '{key}'".format(key=key))
+            raise ValueError(f"multiple values for {key!r}")
 
     verification_data = {key: values[0] for key, values in query.items()}
     return parsed_url.path, verification_data

tests/helpers/views.py

@@ -11,7 +11,7 @@ def __init__(self, view_name, app_name='rest_registration'):
 
     @property
     def full_view_name(self):
-        return '{self.app_name}:{self.view_name}'.format(self=self)
+        return f"{self.app_name}:{self.view_name}"
 
     @property
     def view_url(self):

tests/unit_tests/api/views/base.py

@@ -38,11 +38,7 @@ def assert_response(
             self, response, expected_valid_response=True,
             expected_status_code=None):
         status_code = response.status_code
-        msg_format = "Response returned with code {status_code}, body {response.data}"  # noqa: E501
-        msg = msg_format.format(
-            status_code=status_code,
-            response=response,
-        )
+        msg = f"Response returned with code {status_code}, body {response.data}"
         if expected_status_code is not None:
             self.assertEqual(status_code, expected_status_code, msg=msg)
         elif expected_valid_response:
@@ -102,9 +98,9 @@ def _parse_verification_url(self, url, verification_field_names):
 
         for key, values in query.items():
             if not values:
-                raise ValueError("no values for '{key}".format(key=key))
+                raise ValueError(f"no values for {key!r}")
             if len(values) > 1:
-                raise ValueError("multiple values for '{key}'".format(key=key))
+                raise ValueError(f"multiple values for {key!r}")
 
         verification_data = {key: values[0] for key, values in query.items()}
         return parsed_url.path, verification_data

tests/unit_tests/api/views/register/test_register.py

@@ -62,7 +62,7 @@ def parse_custom_verification_url(url, verification_field_names):
     url_path = parsed_url.path.rstrip('/')
     url_segments = url_path.rsplit('/', num_of_fields)
     if len(url_segments) != num_of_fields + 1:
-        raise ValueError("Could not parse {url}".format(url=url))
+        raise ValueError(f"Could not parse {url!r}")
 
     data_segments = url_segments[1:]
     url_path = url_segments[0] + '/'