Add a third motivating example and pre-commit example

README.md

@@ -30,16 +30,35 @@ Example `setup.cfg`:
 line-length = 79
 verbose = true
 single-quotes = false
-# etc, etc.
+# etc, etc...
 ```
 
-## Why does this need to exist?
+This can also be combined with Flake8's configuration:
+
+```
+[flake8]
+# This section configures `flake8`, the python linting utility.
+# See also https://flake8.pycqa.org/en/latest/user/configuration.html
+ignore = E201,E202,E203
+# E201 - whitespace after ‘(‘
+# E202 - whitespace before ‘)’
+# E203 - whitespace before ‘:’
 
-- The current maintainer of black, [refuses](https://github.com/psf/black/pull/633#issuecomment-445477386) to allow a single-quotes option. Due to his own *personal* preference (a preference which most of the Python community do not share).
+# Exclude the git directory and virtualenv directory (as `.env`)
+exclude = .git,.env
+
+[tool:brunette]
+line-length = 79
+# etc, etc...
+```
+
+## Why does this need to exist?
 
-- The current maintainer of black, [refuses](https://github.com/psf/black/issues/683#issuecomment-542731068) to add setup.cfg support. Setup.cfg is the most widely used configuration file for Python projects. The maintainer of that library prefers "project.tolm" few people use at this time due to it's inflexibility and it requiring you to use Poetry, whatever that is.
+- The current maintainer of Black, [refuses](https://github.com/psf/black/pull/633#issuecomment-445477386) to allow a single-quotes option. Due to his own *personal* preference (a preference which most of the Python community do not share).
 
+- The current maintainer of Black, [refuses](https://github.com/psf/black/issues/683#issuecomment-542731068) to add setup.cfg support. Setup.cfg is the most widely used configuration file for Python projects. The maintainer of that library prefers "project.tolm" few people use at this time due to it's inflexibility and it requiring you to use Poetry, whatever that is.
 
+- The current configuration file format as adopted by Black may conflict with the new _build isolation_ context with `pip`.  To avoid this, the use of a `setup.cfg` file is preferred but the policy is under review by the maintainers (https://github.com/pypa/pip/issues/8437#issuecomment-644196428).
 
 ## How to configure in VSCode
 
@@ -57,3 +76,37 @@ In my case this looks like `/home/work/.pyenv/shims/brunette`. Now copy whatever
 ![https://i.imgur.com/6EXoamM.png](https://i.imgur.com/6EXoamM.png)
 
 3. That's it! Now whenever you [format your Python code](https://stackoverflow.com/a/48764668/13405802) brunette will be used.
+
+## How to configure with Pre-Commit (https://pre-commit.com)
+
+1. Run `pip install pre-commit` to install 
+
+2. Add a local repo option for brunette in `.pre-commit-config.yaml`
+
+```
+# See https://pre-commit.com for more information
+# See https://pre-commit.com/hooks.html for more hooks
+repos:
+  - repo: local
+    hooks:
+      - id: brunette
+        name: brunette
+        description: Run Brunette on Python code (fork of Black).
+        entry: brunette --config=setup.cfg
+        language: system
+        types: [python]
+  # Drop-in replacement for black with brunette
+  # - repo: https://github.com/psf/black
+  #   rev: stable
+  #   hooks:
+  #     - id: black
+  #       language_version: python3.6
+  - repo: https://gitlab.com/pycqa/flake8
+    rev: 3.8.1
+    hooks:
+      - id: flake8
+```
+
+3. Run `pre-commit install` to install the Git pre-commit hook
+
+3. Run `pre-commit run` to validate all files