change: unique source code span and codeline IDs

[brynpickering]

Is your change request related to a problem? Please describe.

When using show_source the code snippet has a span and codelineno ID per line, e.g. </span><span id="__span-0-35"><a id="__codelineno-0-35" name="__codelineno-0-35"></a>.

If referencing the same line in two different code snippets (e.g. the same line from two different modules given on the same page or the same method being referenced as it is inherited from the parent abstract base class in a module), there are duplicate instances of the same spand and codeline ID. Accessibility checkers complain about this, and with good reason!

Describe the solution you'd like

Ideally, each source code snippet would have some kind of unique code (maybe a random hash?) that is added to the IDs.

Describe alternatives you've considered

For now, I've simply ignored these types of IDs in my Accessibility checker, but it is non-ideal...

Additional context

[pawamoy]

Hi @brynpickering, thanks for the change request.

Can you share your config, particularly pymdownx's?

[brynpickering]

Sure:

markdown_extensions:
  - admonition
  - attr_list
  - mkdocs-click
  - tables
  - pymdownx.emoji:
      emoji_index: !!python/name:material.extensions.emoji.twemoji
      emoji_generator: !!python/name:material.extensions.emoji.to_svg
  - pymdownx.highlight:
      anchor_linenums: true
      line_spans: __span
      pygments_lang_class: true
  - pymdownx.inlinehilite:
      style_plain_text: shell
  - pymdownx.details
  - pymdownx.superfences
  - pymdownx.snippets
  - pymdownx.tabbed:
      alternate_style: true
  - toc:
      permalink: "#"
      toc_depth: 3
  - pymdownx.arithmatex:
      generic: true

hooks:
  - docs/static/hooks.py
plugins:
  - search
  - autorefs
  - mkdocs-jupyter:
      include: ["examples/*.ipynb"]
      allow_errors: false
      kernel_name: ntem_synthpop
      include_source: True
      execute: false
  - mkdocstrings:
      default_handler: python
      handlers:
        python:
          options:
            docstring_section_style: spacy
            show_bases: true
            filters:
              - "!^_"
            merge_init_into_class: true
            show_if_no_docstring: true
            signature_crossrefs: true
            show_root_toc_entry: false
            show_signature_annotations: false
          paths: [src]
          import:
            - https://docs.python.org/3/objects.inv