Add pre-commit, editorconfig, black, isort, flake8

.editorconfig

@@ -0,0 +1,18 @@
+# This file is for unifying the coding style for different editors and IDEs
+# editorconfig.org
+
+root = true
+
+[*]
+end_of_line = lf
+charset = utf-8
+insert_final_newline = true
+trim_trailing_whitespace = true
+indent_style = space
+max_line_length = 90
+
+[**.py]
+indent_size = 4
+
+[**.yaml]
+indent_size = 2

.flake8

@@ -0,0 +1,4 @@
+[flake8]
+max-line-length = 90
+extend-ignore = E203, E231, E265, E266, E402, E501, E731
+select = B,C,E,F,W,T4,B9

.git-blame-ignore-revs

@@ -0,0 +1 @@
+# refs to ignore during git blame, use with --ignore-revs-file

.isort.cfg

@@ -0,0 +1,7 @@
+[settings]
+multi_line_output = 3
+include_trailing_comma = True
+force_grid_wrap = 0
+use_parentheses = True
+ensure_newline_before_comments = True
+line_length = 90

.pre-commit-config.yaml

@@ -0,0 +1,34 @@
+exclude: ^(src/octoprint/vendor/|src/octoprint/static/js/lib|src/octoprint/static/vendor|tests/static/js/lib|tests/util/_files|docs/|scripts/|translations/|.*\.css|.*\.svg)
+repos:
+  - repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: v2.3.0
+    hooks:
+      - id: end-of-file-fixer
+      - id: trailing-whitespace
+      - id: check-case-conflict
+      - id: check-merge-conflict
+      - id: fix-encoding-pragma
+  - repo: https://github.com/OctoPrint/codemods
+    rev: devel
+    hooks:
+      - id: codemod_dict_to_literal
+        stages: ["manual"]
+      - id: codemod_set_to_literal
+        stages: ["manual"]
+      - id: codemod_not_in
+        stages: ["manual"]
+  - repo: https://github.com/pre-commit/mirrors-isort
+    rev: v5.5.4
+    hooks:
+      - id: isort
+  - repo: https://github.com/psf/black
+    rev: stable
+    hooks:
+      - id: black
+        args: ["--config", "black.toml"]
+  - repo: https://gitlab.com/pycqa/flake8
+    rev: 3.8.1
+    hooks:
+      - id: flake8
+        additional_dependencies:
+          - flake8-bugbear

_config.yml

@@ -41,6 +41,10 @@ exclude:
 - .github
 - .asset-cache
 - _build
+- .editorconfig
+- .git-blame-ignore-revs
+- .pre-commit-config.yaml
+- black.toml
 
 plugins:
 - jekyll-redirect-from

black.toml

@@ -0,0 +1,10 @@
+[tool.black]
+line-length = 90
+include = '''
+
+(
+    (
+      .github
+    ).*\.pyi?$
+)
+'''