BLD: Use Black.

Author: Scott Sanderson

.pre-commit-config.yaml

@@ -22,3 +22,9 @@ repos:
     rev: v4.3.16
     hooks:
       - id: isort
+
+  - repo: https://github.com/ambv/black
+    rev: stable
+    hooks:
+    - id: black
+      language_version: python3.6

docs/conf.py

@@ -19,14 +19,14 @@
 
 # -- Project information -----------------------------------------------------
 
-project = 'interface'
-copyright = '2018, Scott Sanderson'
-author = 'Scott Sanderson'
+project = "interface"
+copyright = "2018, Scott Sanderson"
+author = "Scott Sanderson"
 
 # The short X.Y version
-version = ''
+version = ""
 # The full version, including alpha/beta/rc tags
-release = '1.4.0'
+release = "1.4.0"
 
 
 # -- General configuration ---------------------------------------------------
@@ -39,26 +39,26 @@
 # extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
 # ones.
 extensions = [
-    'sphinx.ext.autodoc',
-    'sphinx.ext.doctest',
-    'sphinx.ext.intersphinx',
-    'sphinx.ext.todo',
-    'sphinx.ext.viewcode',
-    'sphinx.ext.napoleon',
-    'sphinx.ext.autosummary',
+    "sphinx.ext.autodoc",
+    "sphinx.ext.doctest",
+    "sphinx.ext.intersphinx",
+    "sphinx.ext.todo",
+    "sphinx.ext.viewcode",
+    "sphinx.ext.napoleon",
+    "sphinx.ext.autosummary",
 ]
 
 # Add any paths that contain templates here, relative to this directory.
-templates_path = ['_templates']
+templates_path = ["_templates"]
 
 # The suffix(es) of source filenames.
 # You can specify multiple suffix as a list of string:
 #
 # source_suffix = ['.rst', '.md']
-source_suffix = '.rst'
+source_suffix = ".rst"
 
 # The master toctree document.
-master_doc = 'index'
+master_doc = "index"
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.
@@ -70,18 +70,18 @@
 # List of patterns, relative to source directory, that match files and
 # directories to ignore when looking for source files.
 # This pattern also affects html_static_path and html_extra_path .
-exclude_patterns = ['_build', 'Thumbs.db', '.DS_Store']
+exclude_patterns = ["_build", "Thumbs.db", ".DS_Store"]
 
 # The name of the Pygments (syntax highlighting) style to use.
-pygments_style = 'sphinx'
+pygments_style = "sphinx"
 
 
 # -- Options for HTML output -------------------------------------------------
 
 # The theme to use for HTML and HTML Help pages.  See the documentation for
 # a list of builtin themes.
 #
-html_theme = 'sphinx_rtd_theme'
+html_theme = "sphinx_rtd_theme"
 
 # Theme options are theme-specific and customize the look and feel of a theme
 # further.  For a list of options available for each theme, see the
@@ -92,7 +92,7 @@
 # Add any paths that contain custom static files (such as style sheets) here,
 # relative to this directory. They are copied after the builtin static files,
 # so a file named "default.css" will overwrite the builtin "default.css".
-html_static_path = ['_static']
+html_static_path = ["_static"]
 
 # Custom sidebar templates, must be a dictionary that maps document names
 # to template names.
@@ -108,7 +108,7 @@
 # -- Options for HTMLHelp output ---------------------------------------------
 
 # Output file base name for HTML help builder.
-htmlhelp_basename = 'interfacedoc'
+htmlhelp_basename = "interfacedoc"
 
 
 # -- Options for LaTeX output ------------------------------------------------
@@ -117,15 +117,12 @@
     # The paper size ('letterpaper' or 'a4paper').
     #
     # 'papersize': 'letterpaper',
-
     # The font size ('10pt', '11pt' or '12pt').
     #
     # 'pointsize': '10pt',
-
     # Additional stuff for the LaTeX preamble.
     #
     # 'preamble': '',
-
     # Latex figure (float) alignment
     #
     # 'figure_align': 'htbp',
@@ -135,19 +132,21 @@
 # (source start file, target name, title,
 #  author, documentclass [howto, manual, or own class]).
 latex_documents = [
-    (master_doc, 'interface.tex', 'interface Documentation',
-     'Scott Sanderson', 'manual'),
+    (
+        master_doc,
+        "interface.tex",
+        "interface Documentation",
+        "Scott Sanderson",
+        "manual",
+    ),
 ]
 
 
 # -- Options for manual page output ------------------------------------------
 
 # One entry per manual page. List of tuples
 # (source start file, name, description, authors, manual section).
-man_pages = [
-    (master_doc, 'interface', 'interface Documentation',
-     [author], 1)
-]
+man_pages = [(master_doc, "interface", "interface Documentation", [author], 1)]
 
 
 # -- Options for Texinfo output ----------------------------------------------
@@ -156,9 +155,15 @@
 # (source start file, target name, title, author,
 #  dir menu entry, description, category)
 texinfo_documents = [
-    (master_doc, 'interface', 'interface Documentation',
-     author, 'interface', 'One line description of project.',
-     'Miscellaneous'),
+    (
+        master_doc,
+        "interface",
+        "interface Documentation",
+        author,
+        "interface",
+        "One line description of project.",
+        "Miscellaneous",
+    ),
 ]
 
 
@@ -167,7 +172,7 @@
 # -- Options for intersphinx extension ---------------------------------------
 
 # Example configuration for intersphinx: refer to the Python standard library.
-intersphinx_mapping = {'https://docs.python.org/': None}
+intersphinx_mapping = {"https://docs.python.org/": None}
 
 # -- Options for todo extension ----------------------------------------------
 

interface/__init__.py

@@ -2,8 +2,8 @@
 from .interface import implements, Interface, InvalidImplementation
 
 __all__ = [
-    'default',
-    'InvalidImplementation',
-    'Interface',
-    'implements',
+    "default",
+    "InvalidImplementation",
+    "Interface",
+    "implements",
 ]

interface/compat.py

@@ -30,18 +30,22 @@ def viewkeys(d):
     def unwrap(func, stop=None):
         # NOTE: implementation is taken from CPython/Lib/inspect.py, Python 3.6
         if stop is None:
+
             def _is_wrapper(f):
-                return hasattr(f, '__wrapped__')
+                return hasattr(f, "__wrapped__")
+
         else:
+
             def _is_wrapper(f):
-                return hasattr(f, '__wrapped__') and not stop(f)
+                return hasattr(f, "__wrapped__") and not stop(f)
+
         f = func  # remember the original func for error reporting
         memo = {id(f)}  # Memoise by id to tolerate non-hashable objects
         while _is_wrapper(func):
             func = func.__wrapped__
             id_func = id(func)
             if id_func in memo:
-                raise ValueError('wrapper loop when unwrapping {!r}'.format(f))
+                raise ValueError("wrapper loop when unwrapping {!r}".format(f))
             memo.add(id_func)
         return func
 
@@ -52,8 +56,7 @@ def _is_wrapper(f):
 
     wraps = functools.wraps
 
-    exec("def raise_from(e, from_):"  # pragma: nocover
-         "    raise e from from_")
+    exec("def raise_from(e, from_):" "    raise e from from_")  # pragma: nocover
 
     def viewkeys(d):
         return d.keys()
@@ -66,21 +69,21 @@ def with_metaclass(meta, *bases):
     # metaclass for one level of class instantiation that replaces itself with
     # the actual metaclass.
     class metaclass(meta):
-
         def __new__(cls, name, this_bases, d):
             return meta(name, bases, d)
-    return type.__new__(metaclass, 'temporary_class', (), {})
+
+    return type.__new__(metaclass, "temporary_class", (), {})
 
 
 __all__ = [
-    'PY2',
-    'PY3',
-    'Parameter',
-    'raise_from',
-    'signature',
-    'unwrap',
-    'viewkeys',
-    'with_metaclass',
-    'wraps',
-    'zip_longest',
+    "PY2",
+    "PY3",
+    "Parameter",
+    "raise_from",
+    "signature",
+    "unwrap",
+    "viewkeys",
+    "with_metaclass",
+    "wraps",
+    "zip_longest",
 ]

interface/default.py

@@ -9,6 +9,7 @@
 class default(object):
     """Default implementation of a function in terms of interface methods.
     """
+
     def __init__(self, implementation):
         self.implementation = implementation
 
@@ -30,17 +31,19 @@ class UnsafeDefault(UserWarning):
         " part of {iface}."
     )
 
-    def warn_if_defaults_use_non_interface_members(interface_name,
-                                                   defaults,
-                                                   members):
+    def warn_if_defaults_use_non_interface_members(interface_name, defaults, members):
         """Warn if an interface default uses non-interface members of self.
         """
         for method_name, attrs in non_member_attributes(defaults, members):
-            warnings.warn(_DEFAULT_USES_NON_INTERFACE_MEMBER_TEMPLATE.format(
-                iface=interface_name,
-                method=method_name,
-                non_members=bulleted_list(attrs),
-            ), category=UnsafeDefault, stacklevel=3)
+            warnings.warn(
+                _DEFAULT_USES_NON_INTERFACE_MEMBER_TEMPLATE.format(
+                    iface=interface_name,
+                    method=method_name,
+                    non_members=bulleted_list(attrs),
+                ),
+                category=UnsafeDefault,
+                stacklevel=3,
+            )
 
     def non_member_attributes(defaults, members):
         from .typed_signature import TypedSignature
@@ -90,12 +93,14 @@ def accessed_attributes_of_local(f, local_name):
         # It will **NOT** find usages in which ``local_name`` is aliased to
         # another name.
         for first, second in sliding_window(instrs, 2):
-            if first.opname == 'LOAD_FAST' and first.argval == local_name:
-                if second.opname in ('LOAD_ATTR', 'LOAD_METHOD', 'STORE_ATTR'):
+            if first.opname == "LOAD_FAST" and first.argval == local_name:
+                if second.opname in ("LOAD_ATTR", "LOAD_METHOD", "STORE_ATTR"):
                     used.add(second.argval)
         return used
 
+
 else:  # pragma: nocover-py3
+
     def warn_if_defaults_use_non_interface_members(*args, **kwargs):
         pass
 

interface/functional.py

@@ -12,6 +12,7 @@
 def complement(f):
     def not_f(*args, **kwargs):
         return not f(*args, **kwargs)
+
     return not_f
 
 
@@ -28,10 +29,7 @@ def valfilter(f, d):
 
 
 def dzip(left, right):
-    return {
-        k: (left.get(k), right.get(k))
-        for k in viewkeys(left) & viewkeys(right)
-    }
+    return {k: (left.get(k), right.get(k)) for k in viewkeys(left) & viewkeys(right)}
 
 
 def sliding_window(iterable, n):