tools: add md-to-ipynb converter script

scripts/md_to_ipynb.py

@@ -0,0 +1,139 @@
+"""
+Convert grpo_vertex_v3.md → grpo_vertex_v3.ipynb
+
+Parses markdown with ```python fenced code blocks into Jupyter notebook cells.
+- ```python blocks → code cells
+- Everything else → markdown cells
+- Consecutive markdown sections are merged into single cells
+- Empty cells are skipped
+"""
+
+import json
+import re
+import sys
+from pathlib import Path
+
+
+def md_to_notebook(md_text: str) -> dict:
+    """Parse markdown into notebook cells."""
+    cells = []
+    
+    # Split on ```python and ``` boundaries
+    # We need to track whether we're inside a code block
+    lines = md_text.split('\n')
+    
+    current_type = 'markdown'  # or 'code'
+    current_lines = []
+    
+    for line in lines:
+        if line.strip() == '```python':
+            # Flush current markdown
+            if current_lines and current_type == 'markdown':
+                text = '\n'.join(current_lines).strip()
+                if text:
+                    cells.append(make_markdown_cell(text))
+            current_lines = []
+            current_type = 'code'
+        elif line.strip() == '```' and current_type == 'code':
+            # Flush current code
+            if current_lines:
+                code = '\n'.join(current_lines)
+                # Remove trailing whitespace but keep structure
+                code = code.rstrip()
+                if code:
+                    cells.append(make_code_cell(code))
+            current_lines = []
+            current_type = 'markdown'
+        else:
+            current_lines.append(line)
+    
+    # Flush remaining
+    if current_lines:
+        text = '\n'.join(current_lines).strip()
+        if text:
+            if current_type == 'code':
+                cells.append(make_code_cell(text))
+            else:
+                cells.append(make_markdown_cell(text))
+    
+    # Build notebook
+    notebook = {
+        "nbformat": 4,
+        "nbformat_minor": 5,
+        "metadata": {
+            "kernelspec": {
+                "display_name": "Python 3 (ipykernel)",
+                "language": "python",
+                "name": "python3"
+            },
+            "language_info": {
+                "name": "python",
+                "version": "3.10.0",
+                "mimetype": "text/x-python",
+                "file_extension": ".py"
+            }
+        },
+        "cells": cells
+    }
+    
+    return notebook
+
+
+def make_code_cell(source: str) -> dict:
+    """Create a code cell."""
+    return {
+        "cell_type": "code",
+        "execution_count": None,
+        "metadata": {},
+        "outputs": [],
+        "source": source.split('\n')  # Will be joined with \n later
+    }
+
+
+def make_markdown_cell(source: str) -> dict:
+    """Create a markdown cell."""
+    return {
+        "cell_type": "markdown",
+        "metadata": {},
+        "source": source.split('\n')
+    }
+
+
+def format_notebook(notebook: dict) -> str:
+    """
+    Format notebook JSON with proper source line handling.
+    Each line in source needs a trailing \n except the last.
+    """
+    for cell in notebook["cells"]:
+        lines = cell["source"]
+        if lines:
+            # Add \n to all lines except the last
+            cell["source"] = [line + '\n' for line in lines[:-1]] + [lines[-1]]
+    
+    return json.dumps(notebook, indent=1, ensure_ascii=False)
+
+
+def main():
+    input_path = Path(sys.argv[1]) if len(sys.argv) > 1 else Path("grpo_vertex_v3.md")
+    output_path = input_path.with_suffix('.ipynb')
+    
+    if not input_path.exists():
+        print(f"Error: {input_path} not found")
+        sys.exit(1)
+    
+    md_text = input_path.read_text(encoding='utf-8')
+    notebook = md_to_notebook(md_text)
+    
+    # Stats
+    code_cells = sum(1 for c in notebook["cells"] if c["cell_type"] == "code")
+    md_cells = sum(1 for c in notebook["cells"] if c["cell_type"] == "markdown")
+    
+    output_path.write_text(format_notebook(notebook), encoding='utf-8')
+    
+    print(f"✓ Converted {input_path} → {output_path}")
+    print(f"  {code_cells} code cells, {md_cells} markdown cells")
+    print(f"  Size: {output_path.stat().st_size / 1024:.1f} KB")
+
+
+if __name__ == "__main__":
+    main()