feat: add support for extracting and loading Pyodide packages in interactive examples

Author: CSSFrancis

Examples/Interactive/plot_interactive_fitting.py

@@ -19,6 +19,9 @@
 and the sum curve will jump to the optimal fit.
 Click a component line again to hide its widgets.
 """
+# Packages required when running interactively in Pyodide (docs live mode).
+_PYODIDE_PACKAGES = ["scipy"]
+
 import numpy as np
 from scipy.optimize import curve_fit
 import anyplotlib as apl

anyplotlib/sphinx_anywidget/_scraper.py

@@ -51,6 +51,11 @@
 # Sentinel that marks a code block as interactive.
 _INTERACTIVE_RE = re.compile(r"#\s*interactive\s*$", re.IGNORECASE | re.MULTILINE)
 
+# Pattern that extracts _PYODIDE_PACKAGES = [...] declarations from source.
+_PYODIDE_PACKAGES_RE = re.compile(
+    r"^_PYODIDE_PACKAGES\s*=\s*(\[[^\]]*\])", re.MULTILINE
+)
+
 
 # ---------------------------------------------------------------------------
 # Helpers
@@ -293,11 +298,28 @@ def __call__(self, block, block_vars, gallery_conf):
 
                 if python_src:
                     data_src = _html_escape(_json.dumps(python_src), quote=True)
+
+                    # Detect _PYODIDE_PACKAGES = [...] in the source.
+                    _pkg_attr = ""
+                    m = _PYODIDE_PACKAGES_RE.search(python_src)
+                    if m:
+                        try:
+                            import ast as _ast
+                            pkgs = _ast.literal_eval(m.group(1))
+                            if pkgs:
+                                _pkg_attr = (
+                                    f' data-pyodide-packages='
+                                    f'"{_html_escape(_json.dumps(pkgs), quote=True)}"'
+                                )
+                        except Exception:
+                            pass
+
                     python_block = (
                         f'<script type="text/x-python"'
                         f' data-fig-id="{fig_id}"'
                         f' data-fig-index="{fig_index}"'
                         f' data-src-file="{Path(src_file).stem}"'
+                        f'{_pkg_attr}'
                         f' data-src="{data_src}"></script>'
                     )
                     rst += "\n\n.. raw:: html\n\n    " + python_block + "\n\n"

anyplotlib/sphinx_anywidget/static/anywidget_bridge.js

@@ -237,7 +237,7 @@ print('[sphinx_anywidget] anywidget monkey-patch installed')
 
     // 8. Collect text/x-python script blocks, group by src-file so each
     //    example source runs exactly once even with multiple figures.
-    const srcGroups = new Map();  // srcFile → { src, pairs: [{figId, figIndex}] }
+    const srcGroups = new Map();  // srcFile → { src, pairs: [{figId, figIndex}], packages: [] }
 
     for (const script of document.querySelectorAll(
         'script[type="text/x-python"][data-fig-id]')) {
@@ -246,9 +246,14 @@ print('[sphinx_anywidget] anywidget monkey-patch installed')
       const figIndex = parseInt(script.dataset.figIndex || '0', 10);
       let src = '';
       try { src = JSON.parse(script.dataset.src || 'null') || ''; } catch (_) {}
-
-      if (!srcGroups.has(srcFile)) srcGroups.set(srcFile, { src, pairs: [] });
-      srcGroups.get(srcFile).pairs.push({ figId, figIndex });
+      let packages = [];
+      try { packages = JSON.parse(script.dataset.pyodidePackages || 'null') || []; } catch (_) {}
+
+      if (!srcGroups.has(srcFile)) srcGroups.set(srcFile, { src, pairs: [], packages });
+      const grp = srcGroups.get(srcFile);
+      grp.pairs.push({ figId, figIndex });
+      // Merge any packages declared by any script tag for this source file.
+      for (const p of packages) if (!grp.packages.includes(p)) grp.packages.push(p);
     }
 
     for (const g of srcGroups.values())
@@ -257,10 +262,19 @@ print('[sphinx_anywidget] anywidget monkey-patch installed')
     // 9. Run each example source once, assign _anywidget_fig_id in creation
     //    order, then push current state into the matching iframes.
     const _execErrors = [];
-    for (const [srcFile, { src, pairs }] of srcGroups) {
+    for (const [srcFile, { src, pairs, packages }] of srcGroups) {
       const figIdList = JSON.stringify(pairs.map(p => p.figId));
       console.info(`[sphinx_anywidget] running: ${srcFile} (${pairs.length} figure(s))`);
       const _srcFileRepr = JSON.stringify(srcFile);
+
+      // Load any extra packages declared by this example (e.g. scipy).
+      if (packages.length > 0) {
+        console.info(`[sphinx_anywidget] loading extra packages for ${srcFile}:`, packages);
+        await _step(`load packages for ${srcFile}`,
+          pyodide.loadPackage(packages));
+        console.info(`[sphinx_anywidget] extra packages loaded for ${srcFile}`);
+      }
+
       try {
         await pyodide.runPythonAsync(`
 import anywidget as _aw