Run black over the codebase (#1760)

* Run black over the codebase; update flake8 config; add pyproject.toml for black.

* Add changelog snippet.

* Fix pyproject.toml values.

docs/releases/upcoming/1760.feature.rst

@@ -0,0 +1 @@
+Used Black to ensure a uniform codestyle for TraitsUI. (#1760)

docs/source/conf.py

@@ -19,7 +19,7 @@
 # If your extensions are in another directory, add it here. If the directory
 # is relative to the documentation root, use os.path.abspath to make it
 # absolute, like shown here.
-#sys.path.append(os.path.abspath('some/directory'))
+# sys.path.append(os.path.abspath('some/directory'))
 
 # General configuration
 # ---------------------
@@ -51,30 +51,30 @@
 
 # There are two options for replacing |today|: either, you set today to some
 # non-false value, then it is used:
-#today = ''
+# today = ''
 # Else, today_fmt is used as the format for a strftime call.
 today_fmt = '%B %d, %Y'
 
 # List of documents that shouldn't be included in the build.
-#unused_docs = []
+# unused_docs = []
 
 # List of directories, relative to source directories, that shouldn't be searched
 # for source files.
-#exclude_dirs = []
+# exclude_dirs = []
 
 # The reST default role (used for this markup: `text`) to use for all documents.
-#default_role = None
+# default_role = None
 
 # If true, '()' will be appended to :func: etc. cross-reference text.
-#add_function_parentheses = True
+# add_function_parentheses = True
 
 # If true, the current module name will be prepended to all description
 # unit titles (such as .. function::).
-#add_module_names = True
+# add_module_names = True
 
 # If true, sectionauthor and moduleauthor directives will be shown in the
 # output. They are ignored by default.
-#show_authors = False
+# show_authors = False
 
 # The name of the Pygments (syntax highlighting) style to use.
 pygments_style = 'sphinx'
@@ -86,29 +86,28 @@
 # The style sheet to use for HTML and HTML Help pages. A file of that name
 # must exist either in Sphinx' static/ path, or in one of the custom paths
 # given in html_static_path.
-#html_style = 'default.css'
+# html_style = 'default.css'
 
 # The name for this set of Sphinx documents.  If None, it defaults to
 # "<project> v<release> documentation".
 html_title = "TraitsUI {} Documentation".format(version.split('.')[0])
 
 # A shorter title for the navigation bar.  Default is the same as html_title.
-#html_short_title = None
+# html_short_title = None
 
 # The name of an image file (within the static path) to place at the top of
 # the sidebar.
-#html_logo = "e-logo-rev.png"
+# html_logo = "e-logo-rev.png"
 
 # The name of an image file (within the static path) to use as favicon of the
 # docs.  This file should be a Windows icon file (.ico) being 16x16 or 32x32
 # pixels large.
-#html_favicon = "favicon.ico"
+# html_favicon = "favicon.ico"
 
 # 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',
-                    os.path.join('tutorials', 'code_snippets')]
+html_static_path = ['_static', os.path.join('tutorials', 'code_snippets')]
 
 # If not '', a 'Last updated on:' timestamp is inserted at every page bottom,
 # using the given strftime format.
@@ -119,31 +118,31 @@
 html_use_smartypants = True
 
 # Custom sidebar templates, maps document names to template names.
-#html_sidebars = {}
+# html_sidebars = {}
 
 # Additional templates that should be rendered to pages, maps page names to
 # template names.
-#html_additional_pages = {}
+# html_additional_pages = {}
 
 # If false, no module index is generated.
 html_use_modindex = False
 
 # If false, no index is generated.
-#html_use_index = False
+# html_use_index = False
 
 # If true, the index is split into individual pages for each letter.
-#html_split_index = False
+# html_split_index = False
 
 # If true, the reST sources are included in the HTML build as _sources/<name>.
-#html_copy_source = True
+# html_copy_source = True
 
 # If true, an OpenSearch description file will be output, and all pages will
 # contain a <link> tag referring to it.  The value of this option must be the
 # base URL from which the finished HTML is served.
-#html_use_opensearch = ''
+# html_use_opensearch = ''
 
 # If nonempty, this is the file name suffix for HTML files (e.g. ".xhtml").
-#html_file_suffix = ''
+# html_file_suffix = ''
 
 # Output file base name for HTML help builder.
 htmlhelp_basename = 'Traitsuidoc'
@@ -156,6 +155,7 @@
     html_theme = 'enthought'
 except ImportError as exc:
     import warnings
+
     msg = '''Can't find Enthought Sphinx Theme, using default.
             Exception was: {}
             Enthought Sphinx Theme can be downloaded from
@@ -174,24 +174,32 @@
 # #html_theme = 'classic'
 
 # Useful aliases to avoid repeating long URLs.
-extlinks = {'github-demo': (
-    f'https://github.com/enthought/traitsui/tree/{version}/traitsui/examples/demo/%s',
-    'github-demo')
+extlinks = {
+    'github-demo': (
+        f'https://github.com/enthought/traitsui/tree/{version}/traitsui/examples/demo/%s',
+        'github-demo',
+    )
 }
 
 # Options for LaTeX output
 # ------------------------
 
 # The paper size ('letter' or 'a4').
-#latex_paper_size = 'letter'
+# latex_paper_size = 'letter'
 
 # The font size ('10pt', '11pt' or '12pt').
-#latex_font_size = '10pt'
+# latex_font_size = '10pt'
 
 # Grouping the document tree into LaTeX files. List of tuples
 # (source start file, target name, title, author, document class [howto/manual]).
 latex_documents = [
-  ('index', 'TraitsUI.tex', 'TraitsUI 4 User Manual', 'Enthought, Inc.', 'manual'),
+    (
+        'index',
+        'TraitsUI.tex',
+        'TraitsUI 4 User Manual',
+        'Enthought, Inc.',
+        'manual',
+    ),
 ]
 
 # The name of an image file (relative to this directory) to place at the top of
@@ -201,21 +209,19 @@
 
 # For "manual" documents, if this is true, then toplevel headings are parts,
 # not chapters.
-#latex_use_parts = False
+# latex_use_parts = False
 
 # Additional stuff for the LaTeX preamble.
-#latex_preamble = ''
+# latex_preamble = ''
 
 # Documents to append as an appendix to all manuals.
-#latex_appendices = []
+# latex_appendices = []
 
 # If false, no module index is generated.
-#latex_use_modindex = True
+# latex_use_modindex = True
 
 # Autodoc options
-autodo_mock_imports = [
-    "wx", "PySide", "PyQt", "PyQt5"
-]
+autodo_mock_imports = ["wx", "PySide", "PyQt", "PyQt5"]
 
 # Intersphinx configuration
 intersphinx_mapping = {

docs/source/traitsui_user_manual/examples/handler_override.py

@@ -16,7 +16,6 @@
 
 
 class TC_Handler(Handler):
-
     def setattr(self, info, object, name, value):
         Handler.setattr(self, info, object, name, value)
         info.object._updated = True

docs/source/traitsui_user_manual/examples/key_bindings.py

@@ -34,7 +34,7 @@
 
 
 class CodeHandler(Handler):
-    """ Handler class for bound methods. """
+    """Handler class for bound methods."""
 
     def save_file(self, info):
         info.object.status = "save file"

docs/source/traitsui_user_manual/examples/mixed_styles.py

@@ -22,17 +22,17 @@ class MixedStyles(HasTraits):
     position_type = Enum("Full-Time", "Part-Time", "Contract")
 
     traits_view = View(
-         Group(
-             Item(name='first_name'),
-             Item(name='last_name'),
-             Group(
-                 Item(name='department'),
-                 Item(name='position_type', style='custom'),
-                 style='simple',
-             ),
-         ),
-         title='Mixed Styles',
-         style='readonly',
+        Group(
+            Item(name='first_name'),
+            Item(name='last_name'),
+            Group(
+                Item(name='department'),
+                Item(name='position_type', style='custom'),
+                style='simple',
+            ),
+        ),
+        title='Mixed Styles',
+        style='readonly',
     )
 
 

docs/source/traitsui_user_manual/examples/tree_editor.py

@@ -12,11 +12,25 @@
 
 from traits.api import HasTraits, Instance, List, Str, Regex
 from traitsui.api import (
-    Action, Group, Handler, HGroup, Item, Menu, Separator, TreeEditor,
-    TreeNode, View, VSplit,
+    Action,
+    Group,
+    Handler,
+    HGroup,
+    Item,
+    Menu,
+    Separator,
+    TreeEditor,
+    TreeNode,
+    View,
+    VSplit,
 )
 from traitsui.editors.tree_editor import (
-    NewAction, CopyAction, CutAction, PasteAction, DeleteAction, RenameAction,
+    NewAction,
+    CopyAction,
+    CutAction,
+    PasteAction,
+    DeleteAction,
+    RenameAction,
 )
 
 
@@ -88,7 +102,6 @@ class Owner(HasTraits):
 
 
 class TreeHandler(Handler):
-
     def employee_department(self, editor, object):
         dept = editor.get_parent(object)
         print(f'{object.name} works in the {dept.name} department.')
@@ -176,8 +189,8 @@ def employee_department(self, editor, object):
     handler=TreeHandler(),
     buttons=['Undo', 'OK', 'Cancel'],
     resizable=True,
-    width=.3,
-    height=.3,
+    width=0.3,
+    height=0.3,
 )
 
 if __name__ == '__main__':

docs/source/traitsui_user_manual/scripts/regenerate_example_screenshots.py

@@ -31,7 +31,7 @@
 
 
 def _is_python_file(path):
-    """ Return true if the given path is (public) non-test Python file."""
+    """Return true if the given path is (public) non-test Python file."""
     _, basename = os.path.split(path)
     _, ext = os.path.splitext(basename)
     return (
@@ -42,7 +42,7 @@ def _is_python_file(path):
 
 
 def get_python_files(directory):
-    """ Report Python files to be run or to be skipped.
+    """Report Python files to be run or to be skipped.
 
     Returns
     -------
@@ -82,8 +82,7 @@ def replaced_configure_traits(
     screenshot_name=None,
     **args,
 ):
-    """ Mocked configure_traits to launch then close the GUI.
-    """
+    """Mocked configure_traits to launch then close the GUI."""
     ui_kwargs = dict(
         view=view,
         parent=None,
@@ -102,14 +101,14 @@ def replaced_configure_traits(
                 "source",
                 "traitsui_user_manual",
                 "images",
-                screenshot_name
+                screenshot_name,
             )
         )
 
 
 @contextlib.contextmanager
 def replace_configure_traits(screenshot_name):
-    """ Context manager to temporarily replace HasTraits.configure_traits
+    """Context manager to temporarily replace HasTraits.configure_traits
     with a mocked version such that GUI launched are closed soon after they
     are open.
     """
@@ -124,7 +123,7 @@ def replace_configure_traits(screenshot_name):
 
 
 def run_file(file_path):
-    """ Execute a given Python file.
+    """Execute a given Python file.
 
     Parameters
     ----------
@@ -140,8 +139,9 @@ def run_file(file_path):
         "__name__": "__main__",
         "__file__": file_path,
     }
-    with replace_configure_traits(screenshot_name), \
-            mock.patch("sys.argv", [file_path]):
+    with replace_configure_traits(screenshot_name), mock.patch(
+        "sys.argv", [file_path]
+    ):
         # Mock argv: Some example reads sys.argv to allow more arguments
         # But all examples should support being run without additional
         # arguments.

docs/source/tutorials/code_snippets/code_block0.py

@@ -2,16 +2,17 @@
 
 from numpy import cos, sin
 
+
 class Point(object):
-    """ 3D Points objects """
-    x = 0.
-    y = 0.
-    z = 0.
+    """3D Points objects"""
+
+    x = 0.0
+    y = 0.0
+    z = 0.0
 
     def rotate_z(self, theta):
-        """ rotate the point around the Z axis """
-        xtemp =  cos(theta) * self.x + sin(theta) * self.y
+        """rotate the point around the Z axis"""
+        xtemp = cos(theta) * self.x + sin(theta) * self.y
         ytemp = -sin(theta) * self.x + cos(theta) * self.y
         self.x = xtemp
         self.y = ytemp
-