Merge branch 'SciTools:main' into master

.flake8

@@ -0,0 +1,49 @@
+[flake8]
+# References:
+#   https://flake8.readthedocs.io/en/latest/user/configuration.html
+#   https://flake8.readthedocs.io/en/latest/user/error-codes.html
+#   https://pycodestyle.readthedocs.io/en/latest/intro.html#error-codes
+
+max-line-length = 80
+max-complexity = 50
+select = C,E,F,W,B,B950
+ignore =
+    # E203: whitespace before ':'
+    E203,
+    # E226: missing whitespace around arithmetic operator
+    E226,
+    # E231: missing whitespace after ',', ';', or ':'
+    E231,
+    # E402: module level imports on one line
+    E402,
+    # E501: line too long
+    E501,
+    # E731: do not assign a lambda expression, use a def
+    E731,
+    # W503: line break before binary operator
+    W503,
+    # W504: line break after binary operator
+    W504,
+exclude =
+    #
+    # ignore the following directories
+    #
+    .eggs,
+    build,
+    docs/src/sphinxext/*,
+    tools/*,
+    benchmarks/*,
+    #
+    # ignore auto-generated files
+    #
+    _ff_cross_refrences.py,
+    std_names.py,
+    um_cf_map.py,
+    #
+    # ignore third-party files
+    #
+    gitwash_dumper.py,
+    #
+    # convenience imports
+    #
+    lib/iris/common/__init__.py

.git-blame-ignore-revs

@@ -0,0 +1,20 @@
+# Format: numpy array format (#5235)
+c18dcd8dafef0cc7bbbf80dfce66f76a46ce59c5
+
+# style: flake8 (#3755)
+7c86bc0168684345dc475457b1a77dadc77ce9bb
+
+# style: black (#3518)
+ffcfad475e0593e1e40895453cf1df154e5f6f2c
+
+# style: isort (#4174)
+15bbcc5ac3d539cb6e820148b66e7cf55d91c5d2
+
+# style: blacken-docs (#4205)
+1572e180243e492d8ff76fa8cdefb82ef6f90415
+
+# style: sort-all (#4353)
+64705dbc40881233aae45f051d96049150369e53
+
+# style: codespell (#5186)
+417aa6bbd9b10d25cad7def54d47ef4d718bc38d

.git_archival.txt

@@ -0,0 +1,4 @@
+node: $Format:%H$
+node-date: $Format:%cI$
+describe-name: $Format:%(describe:tags=true)$
+ref-names: $Format:%D$

.gitattributes

@@ -0,0 +1 @@
+.git_archival.txt  export-subst

.github/CONTRIBUTING.md

@@ -1,36 +1,13 @@
-How to contribute
-=================
+# Contributing to Iris
 
-We want Iris to be driven by the community - your contributions are
-invaluable to us! This page lists the guidelines for contributors which
-will help ease the process of getting your hard work accepted into Iris,
-and shared back to the world.
+Want to contribute to Iris? But don't know where to start 🤔
 
-Getting started
----------------
+We recommend that you first checkout our advice to [First Time Contributors](https://github.com/SciTools/iris/issues/4133),
+which has some solid suggestions on where to begin.
 
-1. If you've not already got one, sign up for a
-   [GitHub account](https://github.com/signup/free).
-1. Fork the Iris repository, create your new fix/feature branch, and
-   start commiting code.
- - Our
-   [development guide](http://scitools.org.uk/iris/docs/latest/developers_guide/gitwash/git_development.html)
-   has more detail.
-1. Make sure you've added appropriate tests, and that *all* the tests
-   pass.
+Otherwise, head over to our [Developers Guide on Getting Involved](https://scitools-iris.readthedocs.io/en/stable/developers_guide/contributing_getting_involved.html)
+for all the information you need to start on your Iris development journey.
 
+Still need help or advice?
 
-Submitting changes
-------------------
-
-1. Read and sign the Contributor Licence Agreement (CLA).
- - See our [governance page](http://scitools.org.uk/governance.html)
-   for the CLA and what to do with it.
-1. Push your branch to your fork of Iris.
-1. Submit your pull request.
-1. Chillax.
-
-
-If in doubt, please
-[contact us](https://groups.google.com/forum/?fromgroups=#!forum/scitools-iris)
-on our Google Group, and we'll be happy to help you.
+Then join us over on our [Iris GitHub Discussions](https://github.com/SciTools/iris/discussions). We'd love to hear from you!

.github/ISSUE_TEMPLATE/bug-report.md

@@ -0,0 +1,39 @@
+---
+name: "\U0001F41B Bug Report"
+about: Submit a bug report to help us improve Iris
+title: ''
+labels: 'Type: Bug'
+assignees: ''
+
+---
+
+## 🐛 Bug Report
+<!-- Provide a clear description of what the bug is -->
+
+## How To Reproduce
+Steps to reproduce the behaviour:
+
+1. 
+2. 
+3. 
+
+## Expected behaviour
+<!-- A clear and concise description of what you expected to happen -->
+
+## Screenshots
+<!-- If applicable, add screenshots to help explain your problem -->
+
+## Environment 
+ - OS & Version: [e.g., Ubuntu 20.04 LTS]
+ - Iris Version: [e.g., From the command line run `python -c "import iris; print(iris.__version__)"`]
+
+## Additional context
+<!-- Provide any further information to help us understand -->
+<details>
+<summary>Click to expand <b>this section...</b></summary>
+
+```
+Please add additional verbose information in this section e.g., code, output, tracebacks, screenshots etc
+```
+</details>
+

.github/ISSUE_TEMPLATE/config.yml

@@ -0,0 +1,9 @@
+# reference: https://docs.github.com/en/github/building-a-strong-community/configuring-issue-templates-for-your-repository#configuring-the-template-chooser
+blank_issues_enabled: false
+contact_links:
+  -  name: 💬 Iris GitHub Discussions
+     url: https://github.com/SciTools/iris/discussions
+     about: Engage with the Iris community to discuss your issue
+  -  name: ❓ Usage Question
+     url: https://github.com/SciTools/iris/discussions/categories/q-a
+     about: Raise a question about how to use Iris in the Q&A section of Discussions

.github/ISSUE_TEMPLATE/documentation.md

@@ -0,0 +1,12 @@
+---
+name: "\U0001F4DA Documentation"
+about: Report an issue with the Iris documentation
+title: ''
+labels: 'Type: Documentation'
+assignees: ''
+
+---
+
+## 📚 Documentation
+<!-- See https://scitools-iris.readthedocs.io/en/latest/ -->
+<!-- Describe the issue or provide a suggestion for improving the Iris documentation -->

.github/ISSUE_TEMPLATE/feature-request.md

@@ -0,0 +1,25 @@
+---
+name: "✨ Feature Request"
+about: Submit a request for a new feature in Iris
+title: ''
+assignees: ''
+
+---
+
+## ✨ Feature Request
+<!-- Provide a clear and concise description of the feature proposal -->
+
+## Motivation
+<!-- Is your feature request related to an existing issue? -->
+<!-- I'm always frustrated when ... -->
+
+## Additional context
+<!-- Provide any further information to help us understand -->
+<details>
+<summary>Click to expand <b>this section...</b></summary>
+
+```
+Please add additional verbose information in this section e.g., references, screenshots, listings etc
+```
+</details>
+

.github/ISSUE_TEMPLATE/issue.md

@@ -0,0 +1,10 @@
+---
+name: "\U0001F4F0 Custom Issue"
+about: Submit a generic issue to help us improve Iris
+title: ''
+assignees: ''
+
+---
+
+## 📰 Custom Issue
+<!-- Provide a clear description of what the issue is, and we'll try our best to help 😀 -->

.github/dependabot.yml

@@ -0,0 +1,20 @@
+# Reference:
+# - https://docs.github.com/en/code-security/supply-chain-security/keeping-your-dependencies-updated-automatically/keeping-your-actions-up-to-date-with-dependabot
+# - https://docs.github.com/en/code-security/supply-chain-security/keeping-your-dependencies-updated-automatically/configuration-options-for-dependency-updates
+
+version: 2
+updates:
+
+  - package-ecosystem: "github-actions"
+    directories:
+      - "/"
+      - "/.github/workflows/composite/*"
+    schedule:
+      # Check later in the week - the upstream dependabot check in `workflows` runs deliberately early in the week.
+      #  Therefore allowing time for the `workflows` update to be merged-and-released first.
+      interval: "weekly"
+      day: "thursday"
+      time: "01:00"
+      timezone: "Europe/London"
+    labels:
+      - "Bot"

.github/labeler.yml

@@ -0,0 +1,9 @@
+# benchmark_this automatically triggers the benchmark workflow when added by
+#  a user. No triggering happens when GitHub Actions adds the label (this
+#  avoids security vulnerabilities), so alternative triggers for the below
+#  files are therefore included in workflows/benchmarks_run.yml. Automatic
+#  labelling is still included here to make it easier to search pull requests,
+#  and to reinforce the culture of using this label.
+benchmark_this:
+- changed-files:
+  - any-glob-to-any-file: ['requirements/locks/*.lock', "setup.py"]

.github/pull_request_template.md

@@ -0,0 +1,14 @@
+## 🚀 Pull Request
+
+### Description
+<!-- Provide a clear description about your awesome pull request -->
+<!-- Tell us all about your new feature, improvement, or bug fix -->
+
+
+---
+[Consult Iris pull request check list]( https://scitools-iris.readthedocs.io/en/latest/developers_guide/contributing_pull_request_checklist.html)
+
+---
+Add any of the below labels to trigger actions on this PR:
+
+- https://github.com/SciTools/iris/labels/benchmark_this

.github/workflows/benchmarks_report.yml

@@ -0,0 +1,83 @@
+# Post any reports generated by benchmarks_run.yml .
+# Separated for security:
+#  https://securitylab.github.com/research/github-actions-preventing-pwn-requests/
+
+name: benchmarks-report
+run-name: Report benchmark results
+
+on:
+  workflow_run:
+    workflows: [benchmarks-run]
+    types:
+      - completed
+
+jobs:
+  download:
+    runs-on: ubuntu-latest
+    outputs:
+      reports_exist: ${{ steps.unzip.outputs.reports_exist }}
+    steps:
+      - name: Download artifact
+        id: download-artifact
+        # https://docs.github.com/en/actions/using-workflows/events-that-trigger-workflows#using-data-from-the-triggering-workflow
+        uses: actions/github-script@v7
+        with:
+          script: |
+            let allArtifacts = await github.rest.actions.listWorkflowRunArtifacts({
+               owner: context.repo.owner,
+               repo: context.repo.repo,
+               run_id: context.payload.workflow_run.id,
+            });
+            let matchArtifact = allArtifacts.data.artifacts.filter((artifact) => {
+              return artifact.name == "benchmark_reports"
+            })[0];
+            if (typeof matchArtifact != 'undefined') {
+              let download = await github.rest.actions.downloadArtifact({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                artifact_id: matchArtifact.id,
+                archive_format: 'zip',
+              });
+              let fs = require('fs');
+              fs.writeFileSync(`${process.env.GITHUB_WORKSPACE}/benchmark_reports.zip`, Buffer.from(download.data));
+            };
+
+      - name: Unzip artifact
+        id: unzip
+        run: |
+          if test -f "benchmark_reports.zip"; then
+            reports_exist=1
+            unzip benchmark_reports.zip -d benchmark_reports
+          else
+            reports_exist=0
+          fi
+          echo "reports_exist=$reports_exist" >> "$GITHUB_OUTPUT"
+
+      - name: Store artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: benchmark_reports
+          path: benchmark_reports
+
+  post_reports:
+    runs-on: ubuntu-latest
+    needs: download
+    if: needs.download.outputs.reports_exist == 1
+    steps:
+      - name: Checkout repo
+        uses: actions/checkout@v4
+
+      - name: Download artifact
+        uses: actions/download-artifact@v4
+        with:
+          name: benchmark_reports
+          path: .github/workflows/benchmark_reports
+
+      - name: Set up Python
+        # benchmarks/bm_runner.py only needs builtins to run.
+        uses: actions/setup-python@v5
+
+      - name: Post reports
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: python benchmarks/bm_runner.py _gh_post