Add flake8 and git-blame-ignore-revs (#6337)

.git-blame-ignore-revs

@@ -0,0 +1,2 @@
+# Run auto-formatters: https://github.com/jupyter/notebook/pull/6335
+a7717d90f128368296fe3434deba5acd6031edab

.pre-commit-config.yaml

@@ -33,16 +33,16 @@ repos:
         files: \.py$
         args: [--profile=black]
 
-  # - repo: https://github.com/pycqa/flake8
-  #   rev: 4.0.1
-  #   hooks:
-  #     - id: flake8
-  #       additional_dependencies:
-  #         [
-  #           "flake8-bugbear==20.1.4",
-  #           "flake8-logging-format==0.6.0",
-  #           "flake8-implicit-str-concat==0.2.0",
-  #         ]
+  - repo: https://github.com/pycqa/flake8
+    rev: 4.0.1
+    hooks:
+      - id: flake8
+        additional_dependencies:
+          [
+            "flake8-bugbear==20.1.4",
+            "flake8-logging-format==0.6.0",
+            "flake8-implicit-str-concat==0.2.0",
+          ]
 
   - repo: https://github.com/sirosen/check-jsonschema
     rev: 0.10.2

docs/source/conf.py

@@ -256,16 +256,7 @@ htmlhelp_basename = "JupyterNotebookdoc"
 
 # -- Options for LaTeX output ---------------------------------------------
 
-latex_elements = {
-    # 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',
-}
+latex_elements = {}
 
 # Grouping the document tree into LaTeX files. List of tuples
 # (source start file, target name, title,
@@ -313,7 +304,7 @@ man_pages = [(master_doc, "jupyternotebook", "Jupyter Notebook Documentation", [
 
 # -- Options for link checks ----------------------------------------------
 
-linkcheck_ignore = ["http://127\.0\.0\.1/*"]
+linkcheck_ignore = [r"http://127\.0\.0\.1/*"]
 
 
 # -- Options for Texinfo output -------------------------------------------

notebook/__init__.py

@@ -1,4 +1,4 @@
-from ._version import __version__
+from ._version import __version__  # noqa
 
 
 def _jupyter_server_extension_paths():

setup.cfg

@@ -49,3 +49,17 @@ test =
 [options.entry_points]
 console_scripts =
     jupyter-notebook = notebook.app:main
+
+[flake8]
+ignore = E501, W503, E402
+builtins = c, get_config
+exclude =
+    .cache,
+    .github,
+    docs,
+    setup.py
+enable-extensions = G
+extend-ignore =
+    G001, G002, G004, G200, G201, G202,
+    # black adds spaces around ':'
+    E203,