Add pre-commit hook, revise setup.cfg

Author: rocky

.pre-commit-config.yaml

@@ -0,0 +1,12 @@
+repos:
+-   repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: v2.0.0
+    hooks:
+    - id: debug-statements
+    - id: end-of-file-fixer
+-   repo: https://github.com/psf/black
+    rev: 20.8b1
+    hooks:
+    - id: black
+      language_version: python3
+      exclude: 'mathicsscript/version.py'

setup.cfg

@@ -1,2 +1,40 @@
 [metadata]
 description-file = README.rst
+
+# Recommended flake8 settings while editing zoom, we use Black for the final
+# linting/say in how code is formatted
+#
+# pip install flake8 flake8-bugbear
+#
+# This will warn/error on things that black does not fix, on purpose.
+
+# This config file MUST be ASCII to prevent weird flake8 dropouts
+
+[flake8]
+# max-line-length setting: NO we do not want everyone writing 120-character lines!
+# We are setting the maximum line length big here because there are longer
+# lines allowed by black in some cases that are forbidden by flake8. Since
+# black has the final say about code formatting issues, this setting is here to
+# make sure that flake8 doesn't fail the build on longer lines allowed by
+# black.
+max-line-length = 120
+max-complexity = 12
+select = E,F,W,C,B,B9
+ignore =
+    # E123 closing bracket does not match indentation of opening bracket's line
+    E123
+    # E203 whitespace before ':' (Not PEP8 compliant, Python Black)
+    E203
+    # E501 line too long (82 > 79 characters) (replaced by B950 from flake8-bugbear,
+    # https://github.com/PyCQA/flake8-bugbear)
+    E501
+    # W503 line break before binary operator (Not PEP8 compliant, Python Black)
+    W503
+    # W504 line break after binary operator (Not PEP8 compliant, Python Black)
+    W504
+    # C901 function too complex - since many of zz9 functions are too complex with a lot
+    # of if branching
+    C901
+    # module level import not at top of file. This is too restrictive. Can't even have a
+    # docstring higher.
+    E402