Reformat and lint files with black and flake8 (#168)

* Clean up of main plotting script

Format with black; fix many, many defects identified with pylint

* Change script names to conform with PEP8

Python prefers snake_case for script and module names
and this fixes pylint complaining about this

* Add flake8 and black targets

black target will reformat all Python scripts
flake8 will run linter on all Python scripts

* Reformat plotting script to improve linting

Passes flake8 (required) and most of pylint (recommended)

* Reformat to improve linting

Pass flake8 (required) and most of pylint (recommended)

* Add notes on Python formatting

black should be used for formatting
scripts must be error free with flake8

* Add flake8 run to actions

* Fix network test and trailing spaces

* Fix strange unicode chars in print string

* Fix name of Python2 http server module

* Refactor to avoid globals

pylint checks pushed an implementation where most code was inside the main() function,
however this caused a problem with unittest that will only run
tests in the global namespace,
but use of globals is rather nasty

This reimplementaion keeps the argument parsing and test case
generation in a main-ish function,
but returns the test case and then
invokes unittest.main()
which is a much nicer implementation

* Fix syntax for strategy

* Remove strategy matrix

Only need to run flake8 on one platform

* Whitelist codefactor/bandit urlopen()

The urlopen() call in these tests is to the http server that was setup by the
unittest itself, so we know that it's ok

* Fix flake8 error

This was an accident, but it proved that the flake8 GH action
works as we want!

Co-authored-by: Graeme A Stewart <graemes@pcphsft90.dyndns.cern.ch>

.flake8

@@ -0,0 +1,7 @@
+# Minimal flake8 tweak to be compatible with black's line length
+# of 88 characters 
+# https://black.readthedocs.io/en/stable/the_black_code_style.html#line-length
+
+[flake8]
+max-line-length = 88
+extend-ignore = E203

.github/scripts/flake8.sh

@@ -0,0 +1,4 @@
+#! /bin/sh
+# Configure and run flake8 target
+cmake /mnt
+cmake --build . --target flake8

.github/workflows/flake8.yml

@@ -0,0 +1,37 @@
+# Name of the workflow
+name: flake8
+
+# Controls when the action will run. Triggers the workflow on push or pull request
+# events but only for the master and stable branches
+on:
+  push:
+    branches: [ master, stable ]
+  pull_request:
+    branches: [ master, stable ]
+
+# A workflow run is made up of one or more jobs that can run sequentially or in parallel
+jobs:
+    # Main building and testing
+    build-test:
+      # The type of runner that the job will run on
+      runs-on: ubuntu-latest
+
+      # Steps represent a sequence of tasks that will be executed as part of the job
+      steps:
+      # Checks-out our repository under $GITHUB_WORKSPACE, so our job can access it
+      - uses: actions/checkout@v2
+
+      # Sets up useful environment variables
+      - name: Setup environment variables
+        run: |
+          echo "::set-env name=DIMAGE::hepsoftwarefoundation/u20-dev"
+        env:
+          PLATFORM: u20-dev
+
+      # Pulls the associated Docker image
+      - name: Docker pull
+        run: docker pull $DIMAGE
+
+      # Builds the code and runs the test
+      - name: Flake8 Lint
+        run: docker run -v $(pwd):/mnt $DIMAGE /mnt/.github/scripts/flake8.sh

CMakeLists.txt

@@ -94,5 +94,6 @@ add_subdirectory(package)
 #--- create uninstall target ---------------------------------------------------
 include(cmake/prmonUninstall.cmake)
 
-#--- clang-format target -------------------------------------------------------
+#--- code format targets -------------------------------------------------------
 include(cmake/clang-format.cmake)
+include(cmake/python-format.cmake)

cmake/python-format.cmake

@@ -0,0 +1,21 @@
+# Additional target to run python linters and formatters on python scripts
+#
+# Requires black/flake8 to be available in the environment
+
+
+# Get all Python files
+file(GLOB_RECURSE ALL_PYTHON_FILES *.py)
+
+# Black is rather simple because there are no options...
+add_custom_target(
+        black
+        COMMAND black
+        ${ALL_PYTHON_FILES}
+)
+
+add_custom_target(
+        flake8
+        COMMAND flake8
+        --config=${CMAKE_CURRENT_SOURCE_DIR}/.flake8
+        ${ALL_PYTHON_FILES}
+)

doc/CONTRIBUTING.md

@@ -40,10 +40,16 @@ repository.
 
 - the feature should be supported by an integration test
 - the code should be commented as needed so that others can understand it
-- code should be formatted using the *Google* style of `clang-format`
+- C++ code should be formatted using the *Google* style of `clang-format`
   - i.e. `clang-format --style=Google ...`
   - There is a `clang-format` CMake target that will do this automatically so we
     recommend that is run before making the pull request
+- Python code should be formatted with `black` (following the Scikit-HEP
+  recommendation) and should also be clean with the `flake8` linter
+  - See the `.flake8` file for the configuration to be compatible with
+    `black`
+  - There are `black` and `flake8` build targets that will run the
+    formatter and linter respectively
 
 We will review the code before accepting the pull request.