Add pre-commit for formatting, liniting and code checking.

.github/ISSUE_TEMPLATE/config.yml

@@ -1,5 +1,5 @@
 blank_issues_enabled: false
 contact_links:
-  - name: PyPSA Mailing List
-    url: https://groups.google.com/forum/#!forum/pypsa
-    about: Please ask and answer general usage questions here.
+- name: PyPSA Mailing List
+  url: https://groups.google.com/forum/#!forum/pypsa
+  about: Please ask and answer general usage questions here.

.github/workflows/ci.yaml

@@ -12,7 +12,7 @@ on:
     branches:
     - master
   schedule:
-    - cron: "0 5 * * TUE"
+  - cron: "0 5 * * TUE"
 
 jobs:
   build:
@@ -35,18 +35,18 @@ jobs:
     - uses: actions/checkout@v2
 
     - name: Setup Miniconda
-      uses: conda-incubator/setup-miniconda@v2.1.1 
+      uses: conda-incubator/setup-miniconda@v2.1.1
       with: # checks out environment 'test' by default
-          mamba-version: "*"
-          channels: conda-forge,defaults
-          channel-priority: true
+        mamba-version: "*"
+        channels: conda-forge,defaults
+        channel-priority: true
 
-    - name: Install dependencies  
+    - name: Install dependencies
       run: |
         echo -ne "url: ${CDSAPI_URL}\nkey: ${CDSAPI_TOKEN}\n" > ~/.cdsapirc
-        echo -e "  - glpk\n  - ipopt<3.13.3" >> envs/environment.yaml
+        echo -e "- glpk\n- ipopt<3.13.3" >> envs/environment.yaml
         mamba env update -f envs/environment.yaml --name test
-        
+
     - name: Test snakemake workflow
       run: |
         conda list

.pre-commit-config.yaml

@@ -0,0 +1,67 @@
+# SPDX-FileCopyrightText: : 2022 The PyPSA-Eur Authors
+#
+# SPDX-License-Identifier: CC0-1.0
+
+exclude: "^LICENSES"
+
+repos:
+- repo: https://github.com/pre-commit/pre-commit-hooks
+  rev: v4.1.0
+  hooks:
+  - id: check-merge-conflict
+  - id: end-of-file-fixer
+  - id: fix-encoding-pragma
+  - id: mixed-line-ending
+  - id: check-added-large-files
+  args: ['--maxkb=2000']
+
+# Sort package imports alphabetically
+- repo: https://github.com/PyCQA/isort
+  rev: 5.10.1
+  hooks:
+  - id: isort
+    args: ["--profile", "black", "--filter-files"]
+
+# Find common spelling mistakes in comments and docstrings
+- repo: https://github.com/codespell-project/codespell
+  rev: v2.1.0
+  hooks:
+  - id: codespell
+    args: ['--ignore-regex="\b[A-Z]+\b"'] # Ignore capital case words, e.g. country codes
+    types_or: [python, rst, markdown]
+    files: ^(scripts|doc)/
+
+# Formatting with "black" coding style
+- repo: https://github.com/psf/black
+  rev: 21.12b0
+  hooks:
+  # Format Python files
+  - id: black
+  # Format Jupyter Python notebooks
+  - id: black-jupyter
+
+# Do YAML formatting (before the linter checks it for misses)
+- repo: https://github.com/macisamuele/language-formatters-pre-commit-hooks
+  rev: v2.2.0
+  hooks:
+  - id: pretty-format-yaml
+    args: [--autofix, --indent, '2', --preserve-quotes]
+
+# Use yamllint to check for valid YAML files and list syntax errors
+- repo: https://github.com/adrienverge/yamllint.git
+  rev: v1.26.3
+  hooks:
+  - id: yamllint
+    args: [--format, parsable, -c=.yamllint]
+
+# Format Snakemake rule / workflow files
+- repo: https://github.com/snakemake/snakefmt
+  rev: 0.4.4
+  hooks:
+  - id: snakefmt
+
+# Check for FSFE REUSE compliance (licensing)
+- repo: https://github.com/fsfe/reuse-tool
+  rev: v0.14.0
+  hooks:
+  - id: reuse

.readthedocs.yml

@@ -7,5 +7,5 @@ version: 2
 python:
   version: 3.8
   install:
-    - requirements: doc/requirements.txt
+  - requirements: doc/requirements.txt
   system_packages: true

.syncignore-receive

@@ -16,4 +16,4 @@ notebooks
 doc
 cutouts
 data/bundle
-*.nc
+*.nc

.yamllint

@@ -0,0 +1,39 @@
+# SPDX-FileCopyrightText: : 2022 The PyPSA-Eur Authors
+#
+# SPDX-License-Identifier: CC0-1.0
+
+# Configuration is based on and overwrites 'default' configuration
+extends: default
+
+rules:
+  braces:
+    # Do not allow flow mappings using curly braces "{" and "}"
+    forbid: true
+  brackets:
+    max-spaces-inside: 0
+    max-spaces-inside-empty: 0
+  comments:
+    require-starting-space: true
+    min-spaces-from-content: 1
+  # Force correct indentation of comments
+  # yamllint disable-line rule:braces
+  comments-indentation: {}
+  # Do not require a specific document start marker
+  document-start: disable
+  document-end: disable
+  empty-lines:
+    max: 3
+    max-end: 0
+  indentation:
+    spaces: consistent
+    # Consistent indent-sequences clash with environment.yaml exported by conda
+    indent-sequences: whatever
+  # Disallow duplicate keys in listings
+  # yamllint disable-line rule:braces
+  key-duplicates: {}
+  line-length:
+    level: warning
+    max: 88
+  new-line-at-end-of-file: enable
+  truthy:
+    check-keys: false       # Disable truthy check hits on keys like "on": ...