Add ignore-self-only-init option

docs/release_notes.rst

@@ -12,6 +12,7 @@ New Features
 
 * Add support for `property_decorators` config to ignore D401.
 * Add support for Python 3.10 (#554).
+* Add `ignore-self-only-init` config (#560).
 
 6.1.1 - May 17th, 2021
 ---------------------------

docs/snippets/config.rst

@@ -45,6 +45,7 @@ Available options are:
 * ``match_dir``
 * ``ignore_decorators``
 * ``property_decorators``
+* ``ignore_self_only_init``
 
 See the :ref:`cli_usage` section for more information.
 

src/pydocstyle/checker.py

@@ -133,10 +133,12 @@ def check_source(
         ignore_decorators=None,
         property_decorators=None,
         ignore_inline_noqa=False,
+        ignore_self_only_init=False,
     ):
         self.property_decorators = (
             {} if property_decorators is None else property_decorators
         )
+        self.ignore_self_only_init = ignore_self_only_init
         module = parse(StringIO(source), filename)
         for definition in module:
             for this_check in self.checks:
@@ -196,6 +198,21 @@ def check_docstring_missing(self, definition, docstring):
               with a single underscore.
 
         """
+
+        def method_violation():
+            if definition.is_magic:
+                return violations.D105()
+            if definition.is_init:
+                if (
+                    self.ignore_self_only_init
+                    and len(definition.param_names) == 1
+                ):
+                    return None
+                return violations.D107()
+            if not definition.is_overload:
+                return violations.D102()
+            return None
+
         if (
             not docstring
             and definition.is_public
@@ -206,17 +223,7 @@ def check_docstring_missing(self, definition, docstring):
                 Module: violations.D100,
                 Class: violations.D101,
                 NestedClass: violations.D106,
-                Method: lambda: violations.D105()
-                if definition.is_magic
-                else (
-                    violations.D107()
-                    if definition.is_init
-                    else (
-                        violations.D102()
-                        if not definition.is_overload
-                        else None
-                    )
-                ),
+                Method: method_violation,
                 NestedFunction: violations.D103,
                 Function: (
                     lambda: violations.D103()
@@ -1050,6 +1057,7 @@ def check(
     ignore_decorators=None,
     property_decorators=None,
     ignore_inline_noqa=False,
+    ignore_self_only_init=False,
 ):
     """Generate docstring errors that exist in `filenames` iterable.
 
@@ -1069,6 +1077,8 @@ def check(
 
     `ignore_inline_noqa` controls if `# noqa` comments are respected or not.
 
+    `ignore_self_only_init` controls if D107 is reported on __init__ only containing `self`.
+
     Examples
     ---------
     >>> check(['pydocstyle.py'])
@@ -1106,6 +1116,7 @@ def check(
                 ignore_decorators,
                 property_decorators,
                 ignore_inline_noqa,
+                ignore_self_only_init,
             ):
                 code = getattr(error, 'code', None)
                 if code in checked_codes:

src/pydocstyle/cli.py

@@ -43,13 +43,15 @@ def run_pydocstyle():
             checked_codes,
             ignore_decorators,
             property_decorators,
+            ignore_self_only_init,
         ) in conf.get_files_to_check():
             errors.extend(
                 check(
                     (filename,),
                     select=checked_codes,
                     ignore_decorators=ignore_decorators,
                     property_decorators=property_decorators,
+                    ignore_self_only_init=ignore_self_only_init,
                 )
             )
     except IllegalConfiguration as error:

src/pydocstyle/config.py

@@ -180,6 +180,7 @@ class ConfigurationParser:
         'match',
         'match-dir',
         'ignore-decorators',
+        'ignore-self-only-init',
     )
     BASE_ERROR_SELECTION_OPTIONS = ('ignore', 'select', 'convention')
 
@@ -190,6 +191,7 @@ class ConfigurationParser:
         "property,cached_property,functools.cached_property"
     )
     DEFAULT_CONVENTION = conventions.pep257
+    DEFAULT_IGNORE_SELF_ONLY_INIT = False
 
     PROJECT_CONFIG_FILES = (
         'setup.cfg',
@@ -296,6 +298,7 @@ def _get_property_decorators(conf):
                                 list(config.checked_codes),
                                 ignore_decorators,
                                 property_decorators,
+                                config.ignore_self_only_init,
                             )
             else:
                 config = self._get_config(os.path.abspath(name))
@@ -308,6 +311,7 @@ def _get_property_decorators(conf):
                         list(config.checked_codes),
                         ignore_decorators,
                         property_decorators,
+                        config.ignore_self_only_init,
                     )
 
     # --------------------------- Private Methods -----------------------------
@@ -509,9 +513,13 @@ def _merge_configuration(self, parent_config, child_options):
             'match_dir',
             'ignore_decorators',
             'property_decorators',
+            'ignore_self_only_init',
         ):
-            kwargs[key] = getattr(child_options, key) or getattr(
-                parent_config, key
+            child_value = getattr(child_options, key)
+            kwargs[key] = (
+                child_value
+                if child_value is not None
+                else getattr(parent_config, key)
             )
         return CheckConfiguration(**kwargs)
 
@@ -548,6 +556,7 @@ def _create_check_config(cls, options, use_defaults=True):
             'match_dir': "MATCH_DIR_RE",
             'ignore_decorators': "IGNORE_DECORATORS_RE",
             'property_decorators': "PROPERTY_DECORATORS",
+            'ignore_self_only_init': "IGNORE_SELF_ONLY_INIT",
         }
         for key, default in defaults.items():
             kwargs[key] = (
@@ -844,6 +853,12 @@ def _create_option_parser(cls):
             'basic list previously set by --select, --ignore '
             'or --convention.',
         )
+        add_check(
+            '--ignore-self-only-init',
+            default=None,
+            action='store_true',
+            help='ignore __init__ methods which only have a self param.',
+        )
 
         parser.add_option_group(check_group)
 
@@ -911,6 +926,7 @@ def _create_option_parser(cls):
         'match_dir',
         'ignore_decorators',
         'property_decorators',
+        'ignore_self_only_init',
     ),
 )
 

src/pydocstyle/parser.py

@@ -89,6 +89,7 @@ class Definition(Value):
         'decorators',
         'docstring',
         'children',
+        'call_names',
         'parent',
         'skipped_error_codes',
     )  # type: Tuple[str, ...]
@@ -235,6 +236,11 @@ def is_test(self):
         """
         return self.name.startswith('test') or self.name == 'runTest'
 
+    @property
+    def param_names(self):
+        """Return the parameter names."""
+        return self.call_names
+
 
 class NestedFunction(Function):
     """A Python source code nested function."""
@@ -665,8 +671,10 @@ def parse_definition(self, class_):
         name = self.current.value
         self.log.debug("parsing %s '%s'", class_.__name__, name)
         self.stream.move()
+        call_names = []
         if self.current.kind == tk.OP and self.current.value == '(':
             parenthesis_level = 0
+            in_default_arg = False
             while True:
                 if self.current.kind == tk.OP:
                     if self.current.value == '(':
@@ -675,6 +683,15 @@ def parse_definition(self, class_):
                         parenthesis_level -= 1
                         if parenthesis_level == 0:
                             break
+                    elif self.current.value == ',':
+                        in_default_arg = False
+                elif (
+                    parenthesis_level == 1
+                    and self.current.kind == tk.NAME
+                    and not in_default_arg
+                ):
+                    call_names.append(self.current.value)
+                    in_default_arg = True
                 self.stream.move()
         if self.current.kind != tk.OP or self.current.value != ':':
             self.leapfrog(tk.OP, value=":")
@@ -711,7 +728,8 @@ def parse_definition(self, class_):
             decorators,
             docstring,
             children,
-            None,
+            call_names,
+            None,  # parent
             skipped_error_codes,
         )
         for child in definition.children:

src/tests/test_decorators.py

@@ -167,10 +167,10 @@ def %s(self):
                                dunder_all, None, None, '')
 
         cls = parser.Class('ClassName', source, 0, 1, [],
-                           'Docstring for class', children, module, '')
+                           'Docstring for class', children, [], module, '')
 
         return parser.Method(name, source, 0, 1, [],
-                             'Docstring for method', children, cls, '')
+                             'Docstring for method', children, [], cls, '')
 
     def test_is_public_normal(self):
         """Test that methods are normally public, even if decorated."""

src/tests/test_integration.py

@@ -1489,3 +1489,18 @@ def test_comment_with_noqa_plus_docstring_file(env):
     out, _, code = env.invoke()
     assert '' == out
     assert code == 0
+
+
+def test_ignore_self_only_init(env):
+    """Test that ignore_self_only_init works ignores __init__ with only self."""
+    with env.open('example.py', 'wt') as example:
+        example.write(textwrap.dedent("""\
+            class Foo:
+                def __init__(self):
+                    pass
+        """))
+
+    env.write_config(ignore_self_only_init=True, select="D107")
+    out, err, code = env.invoke()
+    assert '' == out
+    assert code == 0