Development

README.md

@@ -26,7 +26,9 @@ Quick cheatsheet for basic Python.
 
 **This is a casual and unpolished personal project, started in Aug '26.**
 
-I wrote and built this from scratch — it started as a few quick-reference explanations on loops and lists for high-school intro-Python students working on their first projects, and evolved from there. I couldn't find a resource my students would consistently use that had:
+I wrote and built this from scratch, not as a complete Python language reference, but as a visualization of my mental model of how Python works.
+
+ It started as a few quick-reference explanations on loops and lists for high-school intro-Python students working on their first independent projects, and evolved from there. I couldn't find a resource my students would consistently use that had:
 
 - simple explanations for beginners without technical jargon
 - no advanced topics that intimidate or overwhelm beginners
@@ -52,12 +54,14 @@ On the homepage there is a compacted quick reference cheatsheet that includes mo
 
 **Add-on libraries** 
 
-- **Utilities** — collections, datetime, random
+- **Utilities** — collections, datetime, math, random, re, time
 - **Data analysis** — csv, matplotlib, NumPy, pandas
 - **APIs** — json, requests
 - **Image editing** — Pillow
 - **Computer vision** — OpenCV
 - **Desktop UIs** — Tkinter
+- **Games** — turtle
+- **Testing** — pytest
 
 ## Site generator
 
@@ -110,6 +114,15 @@ A syntax highlighter, which colors code in the browser. It handles both the stat
 
 A diagram renderer, which draws flowcharts and diagrams from a plain-text description. Fenced `mermaid` blocks in the Markdown are rendered to SVG on page load.
 
+### Essentials / Advanced toggle
+
+A two-option [switch](docs/javascripts/essentials_toggle.js) that lets a reader hide everything beyond a first-pass beginner curriculum. Content is opted into hiding by marking it `data-advanced="true"`:
+
+- On a `##`/`###` heading inside a content page (e.g. functions.md's `## Decorators`), it hides that heading plus every sibling up to the next heading of the same or higher level, and removes the matching entry from the `toc.integrate` sidebar — so there's no dead nav link to something that's hidden.
+- On a homepage card-grid row, it hides just that row; `data-advanced="card"` hides an entire homepage card instead, for a whole linked page rather than one section.
+
+Each marking is independent — there's no shared list of "advanced" topics to keep in sync, just the attribute at each spot in the Markdown. State persists in `localStorage` and applies on every page (also settable via a `?simplified=true`/`false` URL param, for sharing a pre-set link). If a visible link points at a heading that's currently hidden (e.g. collections.md's cheat-sheet table linking to `#tuples`), following it flips the toggle back to Advanced and reveals the target instead of landing on nothing.
+
 ## Theme
 
 ### Custom CSS
@@ -171,13 +184,18 @@ The standard Python test runner, which discovers `test_*` functions across the r
   because it needs editorial judgment a text-only check can't make.
 - `tests/test_accessibility.py` is a static (no-browser) regression check for a specific
   accessibility bug pattern (an `outline: none` with no `:focus-visible` replacement).
+- `tests/test_typos.py` runs [codespell](#codespell) over the site's prose sources.
 - The browser-based accessibility tier (`test_accessibility_browser.py`,
   `test_accessibility_runnable.py`, `test_accessibility_keyboard.py`) renders real pages with
   Playwright and checks: axe-core over representative pages in light/dark mode and at
   mobile/tablet widths; the hand-wired Pyodide runnable blocks (accessible names, keyboard
   focus order, the output live region); and keyboard navigation (skip link, a visible focus
   ring on every tab stop, no positive tabindex, palette toggle reachable). It's the heaviest
   part of the suite — needs `playwright install chromium` above and launches a real browser.
+- `tests/test_essentials_toggle.py` is a browser test (same Playwright setup) for the
+  Essentials/Advanced toggle described above: the default (Advanced) state, that
+  `?simplified=true` hides marked content and carries onto a page's own heading + TOC entry,
+  and the link-recovery behavior for a visible link into hidden content.
 
 ### [Playwright](https://playwright.dev/)
 
@@ -187,6 +205,10 @@ A browser-automation library, which drives a real browser from code to load page
 
 An accessibility rule engine, which scans a rendered page's DOM for WCAG violations. It runs inside the Playwright browser against every fully rendered page.
 
+### [codespell](https://github.com/codespell-project/codespell)
+
+A spell checker aimed at source code and prose, which flags known misspellings against a fixed list rather than words simply missing from a dictionary. `tests/test_typos.py` runs it over the site's page content and editorial docs.
+
 ### Continuous integration
 
 1. Work is done on the `development` branch.

STRUCTURE.md

@@ -138,9 +138,10 @@ staying inline.**
   bold/emphasis markup, not literal underscores, so `### Overriding __init__()` renders (and
   slugifies) as "Overriding **init**()" with the underscores silently eaten. Confirm any heading
   change like this against the real built HTML, not just the source Markdown.
-- **`####` is reserved** for `index.md`'s homepage category boxes and genuinely deep
-  library-page content (e.g. `libraries/pillow.md`'s per-method sections) — most content pages
-  should never need to go past `###`.
+- **`####` is a normal fourth level**, used under the same three conditions as `###` above, for
+  when a `###` section itself needs breaking down further (e.g. `types.md`'s `### int`/`### float`
+  each splitting into `#### Arithmetic`, `#### Convert`, etc.). Used throughout content pages, not
+  just `index.md`'s homepage category boxes or library pages.
 
 ### Homepage keyword deep-links (`index.md`, `libraries/index.md`)
 

docs/about.md

@@ -53,6 +53,25 @@ More about me at [lukasherman.com](https://lukasherman.com).
 
 <div class="pfg-section" markdown="block">
 
+## Other resources
+
+This site isn't a comprehensive Python guide, so here's where to go for more.
+
+For beginners:
+
+- [W3Schools Python Tutorial](https://www.w3schools.com/python/) — syntax reference with a live editor for every example
+- [Real Python](https://realpython.com/) — longer tutorials and articles that go deeper on individual topics
+- [Python's own tutorial](https://docs.python.org/3/tutorial/) — official, terse, but authoritative
+
+For more advanced Python:
+
+- [Effective Python](https://effectivepython.com/) — specific, itemized advice on writing idiomatic, well-structured Python
+- [PEP 8](https://peps.python.org/pep-0008/) — the official style guide
+
+</div>
+
+<div class="pfg-section" markdown="block">
+
 ## Helpful feedback
 
 Spotted a mistake, or want to see something added? Let me know! 

docs/collections.md

@@ -14,7 +14,7 @@ A **collection** is a single object that groups multiple values (like [basic typ
 |------|---------|:-----------------:|:-------:|------------|
 | <a href="#lists">**`list`**</a> | <pre><code class="language-python-ref">["ball", "burmese"]</code></pre> | position # | :material-check:{ .pt-icon-success } | <ul><li>An ordered group of items you can freely add to, remove from, or reorder</li><li>Not sure? Start here — the default, general-purpose choice</li></ul> |
 | <a href="#dictionaries">**`dictionary "dict"`**</a> | <pre><code class="language-python-ref">{&#10;  "species": "ball",&#10;  "length_ft": 5&#10;}</code></pre> | Name of a key | :material-check:{ .pt-icon-success } | <ul><li>Values stored under names ("keys") instead of position, like `species`, `length_ft`</li><li>Use it to look values up by name</li><li>Can't have duplicate keys</li></ul> |
-| <a href="#tuples">**`tuple`**</a> | <pre><code class="language-python-ref">("ball", "burmese")</code></pre> | position # | :material-close:{ .pt-icon-fail } | <ul><li>Like a list, but fixed — can't be changed once created</li><li>Values that should stay exactly as they are, like a coordinate pair</li></ul> |
+| <a href="#tuples">**`tuple`**</a> | <pre><code class="language-python-ref">("ball", "burmese")</code></pre> | position # | :material-close:{ .pt-icon-fail } | <ul><li>Like a list, but it's sequence of items can't be changed once created</li><li>Values that should stay exactly as they are, like a coordinate pair</li></ul> |
 | <a href="#sets">**`set`**</a> | <pre><code class="language-python-ref">{"ball", "burmese"}</code></pre> | Membership (`in`) | :material-check:{ .pt-icon-success } | <ul><li>An unordered group where duplicates are automatically dropped</li><li>Use it for fast "is this in here?" checks</li></ul> |
 
 </div>
@@ -28,10 +28,10 @@ A **collection** is a single object that groups multiple values (like [basic typ
     ```python-ref
     weights = [5, 3, 6]
 
-    type(weights)        # <class 'list'>
+    type(weights)              # <class 'list'>
 
-    isinstance(5, list)  # True
-    isinstance(5, dict)  # False
+    isinstance(weights, list)  # True
+    isinstance(weights, dict)  # False
     ```
 
 <div class="pfg-section" markdown="block">